the science of cables

[werewolf]

Seems like every year or so a new debate begins, concerning cable mythology (really, it is the most appropriate word). Maybe we can shed some light on the debate, by discussing what science ... metallurgy, electrical engineering, etc ... tells us about cables.

I'll start with an anecdote ... "my experience" with cables, if you will. It was an old trick among audio salesman ... even twenty ot thrity years ago ... to swap out RCA cables, and demonstrate what an incredible difference was heard. Even the most tin-eared idiots could hear a difference! Putting aside, for the moment, the strong power of suggestion, lack of variable control, lack of accounting for presence/absence of human memory effects, and all those things that tend to render isolated, uncontrolled subjective observation meaningless ... could a difference actually be heard? The answer was YES ... but it had nothing to do with the cables, per se. The reason was because simply removing an RCA cable and plugging-in a new one would scrape the oxidation and corrosion from the metal at the surface contact, improving the electrical connection. In fact, unplugging a cable and plugging back in the very same cable could create an audible ... and measurable ... difference :)

Let's start by stating the obvious : at both the line-level and speaker-level points in the audio reproduction chain, the signal is electrical in nature ... rather than mechanical or acoustical. I suspect most (perhaps not all) would agree with this point. So the question naturally arises ... what electrical properties of the cable matter?

The answer is remarkably simple. The cable is an electrical network, and it's operating with signals whose electrical wavelength is much, much longer than the cable itself. Therefore, what matters electrically are the parameters in the classic "lumped model" : namely, the cable's Resistance (R), Inductance (L) and Capacitance (C). We can completely discount all transmission line effects ... including standing waves, reflection coefficients, and termination impedance matching (excepting, of course, digital audio transmission ... when the signal is digital, it's bandwidth is orders-of-magnitude higher than analog audio).

How the RLC parameters of the cable effect the signal transmission will depend on the source and load impedance ... in other words, what's driving the cable, and what's on the other end. Knowing these impedances will allow us to measure, or predict, any alteration in the audio band frequency response ... aka magnitude and phase versus frequency ... that a given cable may generate. Linear system theory is a well-established science ... not open to opinion or subjective experience.

Any general conclusions? Sure ... for example, it takes a real effort to significantly impact frequency response at the RCA/line-level, because the load resistance is so high compared to the series elements of R and L. You may, however, want to pay attention to the shunt capcitance in interconnect cables ... it's possible that the capacitance may cause some roll-off in the treble, with a long cable (meaning, high capacitance) and high-ish source impedance. Similarly, you might want to pay attention to the series elements of R and L at speaker-level cables, particulary when driving low impedance loads (like low impedance subs, or highly-capacitive electrostat panels).

Anything else matter about cables? YES ... contact metallurgy, as mentioned. Not only can certain metals oxidize and corrode (impacting that parameter R), but dis-similar metals in a pressure contact can create galvanic effects that demonstrate very measurable ... and potentially audible ... effects. Furthermore, we must include the noise-shielding properties of the cable. How significant? Depends, of course, on how noisy the environment is ;)

What's the bottom line? Let's do some make-pretend Q&A:

Q: Do all cables sound the same?
A: OF COURSE NOT ... but the question is meaningless. A rusty, 30 gauge cable that's 40 feet long will obviously sound different when driving 800 watts to your sub, compared to a short, clean 12 gauge cable.

Q: OK ... so what causes cables to sound different?
A: The only parameters that could matter are RLC, contact metallurgy and noise shielding. The significance of each, depends on the exact environment and application.

Q: What about hyperlitz geometries and specific metal elements?
A: If they don't impact RLC and frequency response over 20kHz, they won't impact the sound ... simply because they can't. If the electrical signal is not altered over a 20kHz bandwidth, the sound coming out of your speakers won't be altered either.

Q: What about the "network boxes" on some super-megabuck cables?
A: Of course they can alter the sound, if they are providing a change to the frequency response (magnitude, phase) of the network operating on 20kHz electrical signals. In other words ... if they are providing some degree of equalization, they can change the "sound". Linear system theory tells us that there is simply no other way to alter the signal, or thereby the "sound" of the cable.

Q. Do all cables ... THAT MEASURE THE SAME ... sound the same?
A. No known reason to believe otherwise :) If you wish to disprove the hypothesis, though, you must of course establish an experiment where all other possible variables are eliminated.

[AVI]

Seems like every year or so a new debate begins, concerning cable mythology (really, it is the most appropriate word). Maybe we can shed some light on the debate, by discussing what science ... metallurgy, electrical engineering, etc ... tells us about cables.

I'll start with an anecdote ... "my experience" with cables, if you will. It was an old trick among audio salesman ... even twenty ot thrity years ago ... to swap out RCA cables, and demonstrate what an incredible difference was heard. Even the most tin-eared idiots could hear a difference! Putting aside, for the moment, the strong power of suggestion, lack of variable control, lack of accounting for presence/absence of human memory effects, and all those things that tend to render isolated, uncontrolled subjective observation meaningless ... could a difference actually be heard? The answer was YES ... but it had nothing to do with the cables, per se. The reason was because simply removing an RCA cable and plugging-in a new one would scrape the oxidation and corrosion from the metal at the surface contact, improving the electrical connection. In fact, unplugging a cable and plugging back in the very same cable could create an audible ... and measurable ... difference :)

Let's start by stating the obvious : at both the line-level and speaker-level points in the audio reproduction chain, the signal is electrical in nature ... rather than mechanical or acoustical. I suspect most (perhaps not all) would agree with this point. So the question naturally arises ... what electrical properties of the cable matter?

The answer is remarkably simple. The cable is an electrical network, and it's operating with signals whose electrical wavelength is much, much longer than the cable itself. Therefore, what matters electrically are the parameters in the classic "lumped model" : namely, the cable's Resistance (R), Inductance (L) and Capacitance (C). We can completely discount all transmission line effects ... including standing waves, reflection coefficients, and termination impedance matching (excepting, of course, digital audio transmission ... when the signal is digital, it's bandwidth is orders-of-magnitude higher than analog audio).

How the RLC parameters of the cable effect the signal transmission will depend on the source and load impedance ... in other words, what's driving the cable, and what's on the other end. Knowing these impedances will allow us to measure, or predict, any alteration in the audio band frequency response ... aka magnitude and phase versus frequency ... that a given cable may generate. Linear system theory is a well-established science ... not open to opinion or subjective experience.

Any general conclusions? Sure ... for example, it takes a real effort to significantly impact frequency response at the RCA/line-level, because the load resistance is so high compared to the series elements of R and L. You may, however, want to pay attention to the shunt capcitance in interconnect cables ... it's possible that the capacitance may cause some roll-off in the treble, with a long cable (meaning, high capacitance) and high-ish source impedance. Similarly, you might want to pay attention to the series elements of R and L at speaker-level cables, particulary when driving low impedance loads (like low impedance subs, or highly-capacitive electrostat panels).

Anything else matter about cables? YES ... contact metallurgy, as mentioned. Not only can certain metals oxidize and corrode (impacting that parameter R), but dis-similar metals in a pressure contact can create galvanic effects that demonstrate very measurable ... and potentially audible ... effects. Furthermore, we must include the noise-shielding properties of the cable. How significant? Depends, of course, on how noisy the environment is ;)

What's the bottom line? Let's do some make-pretend Q&A:

Q: Do all cables sound the same?
A: OF COURSE NOT ... but the question is meaningless. A rusty, 30 gauge cable that's 40 feet long will obviously sound different when driving 800 watts to your sub, compared to a short, clean 12 gauge cable.

Q: OK ... so what causes cables to sound different?
A: The only parameters that could matter are RLC, contact metallurgy and noise shielding. The significance of each, depends on the exact environment and application.

Q: What about hyperlitz geometries and specific metal elements?
A: If they don't impact RLC and frequency response over 20kHz, they won't impact the sound ... simply because they can't. If the electrical signal is not altered over a 20kHz bandwidth, the sound coming out of your speakers won't be altered either.

Q: What about the "network boxes" on some super-megabuck cables?
A: Of course they can alter the sound, if they are providing a change to the frequency response (magnitude, phase) of the network operating on 20kHz electrical signals. In other words ... if they are providing some degree of equalization, they can change the "sound". Linear system theory tells us that there is simply no other way to alter the signal, or thereby the "sound" of the cable.

Q. Do all cables ... THAT MEASURE THE SAME ... sound the same?
A. No known reason to believe otherwise :) If you wish to disprove the hypothesis, though, you must of course establish an experiment where all other possible variables are eliminated.
Do signals travel down different kinds of wire differently ? Example : Round solid core , multi stranded , horizontal shaped solid conducters ?

[werewolf]

The only thing to know ... or wonder ... about cable gemoetry, is how it does, or doesn't, impact resistance, inductance and capcitance. Don't concern yourself with skin effect, for example. Yes, the effect is "real" ... but it's insignificant over audio frequencies.

If an audio cable manufacturer or salesman is praising some new geometry, without discussing RLC impact/significance ... no need to listen any further.

For example ... square, round, rectangular cross-section : the Resistance (R) is determined by cross-sectional area only, not shape. Again ... pay attention to audio freqs only, feel free to ignore skin effect.

Inductance (L) and Capacitance (C) can be influenced by conductor shape (and proximity, of course) ... but any manufacturer worth his salt will tell you how significant the effect is.

Bottom line : if no reference is made to the impact of the geometry on RLC ... there's probably a very good reason ;)

[AVI]

The only thing to know ... or wonder ... about cable gemoetry, is how it does, or doesn't, impact resistance, inductance and capcitance. Don't concern yourself with skin effect, for example. Yes, the effect is "real" ... but it's insignificant over audio frequencies.

If an audio cable manufacturer or salesman is praising some new geometry, without discussing RLC impact/significance ... no need to listen any further.

For example ... square, round, rectangular cross-section : the Resistance (R) is determined by cross-sectional area only, not shape. Again ... pay attention to audio freqs only, feel free to ignore skin effect.

Inductance (L) and Capacitance (C) can be influenced by conductor shape (and proximity, of course) ... but any manufacturer worth his salt will tell you how significant the effect is.

Bottom line : if no reference is made to the impact of the geometry on RLC ... there's probably a very good reason ;)
I asked you this , because I have a stack of white papers one inch thick ... and the entire thing has to do with the shape of the conducters , and how it effects resistance , and capacitance. Interesting reading.

[bobduch]

Jeff, which parameters does dialectric material effect? And how does conductor spacing effect things?

[werewolf]

bob ... dielectric material impacts cpacitance. And sure, lower tends to be better ... but of course there's a point of diminishing returns. For RCA cables, a quick check of source (headunit, processor) resistance and total cable capacitance ... forming a simple RC low-pass filter, to first order ... will tell you if it's low enough.

Spacing impacts capacitance and inductance. Here's a good thread where we discussed inductance over on carsound:

http://www.audiogroupforum.com/csforum/showthread.php?t=2619&highlight=inductance

[chad]

At audio frequencies shape fo the conductor really makes NO difference..... At RF frequencies it makes ALL the difference.

One thing noted. Remember that there IS audio information above 20KHz assuming that your source can reproduce it. If your cable has enough capacatance to roll these frequencies off, say above 40K, which is pretty unlikely you WILL hear a difference. Why? The first harmonic of 30K is... 15K and we CAN hear these harmonics.

I was not a believer in going above 20K till I did my first mic preamp shootout wiht speakers that had an ultra high extension.... Then i realized how much i was being ripped off by the CD only going to 20K.

But I digress, this is coming from a guy with an assload of CD's in his car in MP3 format :)

Chad

[werewolf]

At audio frequencies shape fo the conductor really makes NO difference..... At RF frequencies it makes ALL the difference.

One thing noted. Remember that there IS audio information above 20KHz assuming that your source can reproduce it. If your cable has enough capacatance to roll these frequencies off, say above 40K, which is pretty unlikely you WILL hear a difference. Why? The first harmonic of 30K is... 15K and we CAN hear these harmonics.

I was not a believer in going above 20K till I did my first mic preamp shootout wiht speakers that had an ultra high extension.... Then i realized how much i was being ripped off by the CD only going to 20K.

But I digress, this is coming from a guy with an assload of CD's in his car in MP3 format :)

Chad
Largely agree Chad ... except, of course, the first harmonic of 30K is ... 30K. The second harmonic of 30K is 60K :)

And yes ... bandwidth much beyond half the sampling rate of digital formats is useless. For CD's, that means 22.05kHz.

[fej]

Same reason records are still produced and "audiophiles" still use turntables on their $50k home systems ... no cut off points on either end.

[werewolf]

Same reason records are still produced and "audiophiles" still use turntables on their $50k home systems ... no cut off points on either end.
not quite accurate.

It is true that the analog record (as a recording medium) and analog turntable/stylus (as a playback mechanism) do not have a sharp, hard cut-off frequency ... like a digital recording medium (half the sample rate), but the bandwidth is certainly not unlimited. The vinyl record & stylus absolutely have bandwidth limitations as well ... I'll do some research to uncover accurate numbers.

In other words ... there may be no sharp electrical filters in the turntable chain (although I'll have to think about moving coil cartridges a bit more before I state this definitively), but there certainly are mechanical filters that limit bandwidth.

As an aside ... while analog recording media may have usable bandwidth beyond the most popular digital media (CD), the noise floor of the analog media limit their information (as defined by Shannon) to about an order of magnitude less than even 44.1kHz, 16-bit CD.

[AVI]

not quite accurate.

It is true that the analog record (as a recording medium) and analog turntable/stylus (as a playback medium) do not have a sharp, hard cut-off frequency ... like a digital recording medium (half the sample rate), but the bandwidth is certainly not unlimited. The vinyl record & stylus absolutely have bandwidth limitations as well ... I'll do some research to uncover accurate numbers.

As an aside ... while analog recording media may have usable bandwidth beyond the most popular digital media (CD), the noise floor of the analog media limit their information (as defined by Shannon) to about an order of magnitude less than even 44.1kHz, 16-bit CD.
Ok .... But I have NEVER heard and CD Player at ANY price point , sound nearly as good as a great turntable ;)
Just had to say it , even if it's not relevant :D

[fej]

I believe that it has to do with the perception of information above the 20k hz "barrier" where CD's cut off. We don't necessarily hear it per se as our hearing is limited to the upper teens, possibly to 20k for some but somehow our brain knows it is there .... It may have to do with the harsh cut off point as opposed to, as werewolf puts it, mechanical rolloff of the analog record.

who really knows at this point. I can relate it to a golf club, if you don't like the looks of it when you set it down you will never hit it well. On the other side, if you can get past the initial look and have good results with a club you ignore its "negatives". Same thing with what you hear .. if it sounds better to you that is all that matters.

[T3mpest]

I believe that it has to do with the perception of information above the 20k hz "barrier" where CD's cut off. We don't necessarily hear it per se as out hearing is limited to the upper teens, possibly to 20k for some but somehow our brain knows it is there .... It may have to do with the harsh cut off point as opposed to, as werewolf puts it, mechanical rolloff of the analog record.

who really knows at this point. I can relate it to a golf club, if you don't like the looks of it when you set it down you will never hit it well. On the other side, if you can get past the initial look and have good results with a club you ignore its "negatives". Same thing with what you hear .. if it sounds better to you that is all that matters.

Yes, but isn't finding out WHY it's better important. To continue your analogy, if wouldn't it be nice to have a rating system on golf clubs, one so accurate you could know if you'd like the club before you even held it. If that system could be derived, by math, making it 100% accurate, wouldn't that have advantages over picking up 1000 clubs and giving each a swing, until something felt "right".

Back to the topic. For example, avi likes turntables. If we ran 2 recordings out of a speaker, one from a turntable, and another one from a cd player, and he preferred the turntable, wouldnt' it be nice to know why he preferred it. After all, if we can figure out what it is about a turntable that makes the sound appealing, we could probably apply it to a CD. Just the fact that it's digital vs analog isn't necessarily the issue. We still have real measureable output from the speakers, and if we can get the output that the CD player source causes to be the same as the record player, there would be NO sonic difference, inherently of course.

Sometimes I wonder if audiophiles prefer turntables becuase they know of the inhernet limitations of the CD source. They know it'll cut off a bit over 20k and is actually only playing "parts" of the original song. Whereas a turntable has no inherent gaps in it's timeline and isn't mathmatically structured. It would seem, in some ways, that VERY expensive turntable woudl be essentially perfect in terms of describing the source wave, it has no inherent flaws, only it's ability to follow the path along the record.

[fej]

I would love to know why .. we are all enthusiasts here, but look at the RCA thread (which happens at EVERY audio board at some point, and then usually yearly). What you hear is just not the same as what I hear ... and no science can explain that, well at least at this point. I would love to know why DDD recorded material is usually crystal clear but just seems to lack true warmth (at least IMO) I think it may just be too clean heh. I would like to know why someone listening to their $1500 ipod cable through their $2000 mini amp feels it is better than their $12 cable and $65 amp. Same source material ... what science can you put behind it?

There are facts that werewolf is presenting, there are experiences that AVI and many others are presenting, but at the end of the day we only know for sure what WE like and hear. Nothing science can do about it

[MarkZ]

I believe that it has to do with the perception of information above the 20k hz "barrier" where CD's cut off. We don't necessarily hear it per se as our hearing is limited to the upper teens, possibly to 20k for some but somehow our brain knows it is there .... It may have to do with the harsh cut off point as opposed to, as werewolf puts it, mechanical rolloff of the analog record.

If it doesn't manifest itself as signal transduction in the ear, then the brain simply does not have access to the information to "know it is there". However, I suppose it might be possible that ultrasonic frequencies could potentially have an impact through some sort of IMD mechanism, but that would be tough to attribute to a passive cable...

[MarkZ]

I would love to know why .. we are all enthusiasts here, but look at the RCA thread (which happens at EVERY audio board at some point, and then usually yearly). What you hear is just not the same as what I hear ... and no science can explain that, well at least at this point.

Sure it can. Absent the proper controls, science can explain it with the known mechanisms of the brain that affect our perceptions. That's why all properly conducted listening tests aim to eliminate the brain as a variable. Easier said than done, of course. But not impossible. :)

PS - It's also important to point out that "science" isn't the same as deriving electrical parameters, or what's written in a textbook, or even scientific experiments. Science is nothing more than an application of logic. I kinda wish that people would use the term "logic" instead of "science" in debates such as these, and maybe they wouldn't discard an attempt at a rigorous analysis of the problem in favor of their (flawed) senses.

There's also this notion out there that "science can be wrong". But, by definition, it can't be. Scientific experiments can be performed wrong, or (more common) scientific data can be misinterpreted, but the scientific method is 100% reliable. Unfortunately, a lot of people read a media writeup about a study, and that turns out to be wrong and people conclude that science is fallible. No, the scientist might be fallible, and the media coverage of science is almost always just plain ignorant and misleading, but I digress...

[Thoraudio]

guys... as Jeff has said before in other threads, audio is not the last great unknown field of science....

we're talking about electrical signals and the compression/rarification of air... it's not string theory...



Werewolf, all that aside, how does/can the components of cable affect phasing?

[chad]

Largely agree Chad ... except, of course, the first harmonic of 30K is ... 30K. The second harmonic of 30K is 60K :)

And yes ... bandwidth much beyond half the sampling rate of digital formats is useless. For CD's, that means 22.05kHz.


Damn cold medicine, I have the plauge now :mad:

[chad]

Ok .... But I have NEVER heard and CD Player at ANY price point , sound nearly as good as a great turntable ;)
Just had to say it , even if it's not relevant :D

How-bout a live recording on a 1/2" open reel machine traveling at 30IPS?

Chad

[Thoraudio]

How-bout a live recording on a 1/2" open reel machine traveling at 30IPS?

Chad

I was in a department store doing some Christmas shopping and saw a 'Spirit of St. Louis' cd player/radio that included a fake, working reel to reel :)

I wonder if it improved the sound. :D

[chad]

I have a REAL one I'll give you if you pay shipping. It needs some TLC, It's a 1/4" 2 track and I believe it runs 15IPS at the fastest, I'll need to check. :)

Chad

[T3mpest]

I would love to know why .. we are all enthusiasts here, but look at the RCA thread (which happens at EVERY audio board at some point, and then usually yearly). What you hear is just not the same as what I hear ... and no science can explain that, well at least at this point. I would love to know why DDD recorded material is usually crystal clear but just seems to lack true warmth (at least IMO) I think it may just be too clean heh. I would like to know why someone listening to their $1500 ipod cable through their $2000 mini amp feels it is better than their $12 cable and $65 amp. Same source material ... what science can you put behind it?

There are facts that werewolf is presenting, there are experiences that AVI and many others are presenting, but at the end of the day we only know for sure what WE like and hear. Nothing science can do about it
That's where I'd say your wrong. All your senses work due to your body physically interacting with something. Taste and smell use small particles of the object in question to create 2 different senses, depending on what nerves are touched (nose or tongue). Sight uses light. After all if I see a light with a wavelength of 700nm, according to your beliefs it'd be pretty hard to predict what color I'd see. After all, you see what you see, we can't argue that, what science can we put behind it? ( answer is red ;) )

Sound is nothing more than pressure variations in the air, something that with todays technology is TRIVIAL to measure. Before the signal hits the speaker, it's electricity through a circuit, which honestly, couldn't be any more predicable if it tried. The equipment exists to measure all the parameters of sound, and if every parameter is the same between 2 sources, you body has NOTHING it can base the sounds on to make them sound any different, except personal bias and other distortions of the human mind. Then again, that's what marketing is for. If the 2 waves in question measure identical, or close enough to be within the known limits of human hearing (yes, believe it or not, human hearing doesn't have infinite resolution, it gives up LONG before equipment) they will sound the same to the ear.

[Autiophile]

I don't mean to jump into any argument that can't be resolved on the forum, however, my feeling is that higher end cables simply make me feel like I know where the weak link is in my system. Coming from home audio my goal has always been to know (think) that my components were performing in their intended fasion. I have rewired rooms, used PS audio or Hospital grade outlets, driven grounding poles out in the yard, and spent a decent amount of money on cables.

The net benefit in all of this was confidence. I am confident that my home system is appropriately wired and I feel like it sounds better (even though it may be a placebo effect). In the past year I have started making my own cables for my headphone setup as well as my car. Although they may not be as nice as my MIT or Tara Labs cables, I still have confidence because I know that I made them correctly and they are dependable.

My point is this: Even though the effects of all of this may be in my mind, I perceive a difference. It doesn't have to be expensive or from a well known brand. All the cables need to do is give me confidence that they are not my weak link.

[Thoraudio]

there is something to be said for perception.

[MIAaron]

I don't know, the other night I was hanging out with my nephew and we found shape could have an impact on the sound. We had two mic's built of similar materials but in different shapes. With a GENUINE Dupont Micro-fiber interconnect we found a Campbell mic did provide descent results, but we preferred the more authoritative tone of the larger Progresso. How do you explain that with RLC? :rolleyes:

[MarkZ]

I don't mean to jump into any argument that can't be resolved on the forum, however, my feeling is that higher end cables simply make me feel like I know where the weak link is in my system. Coming from home audio my goal has always been to know (think) that my components were performing in their intended fasion. I have rewired rooms, used PS audio or Hospital grade outlets, driven grounding poles out in the yard, and spent a decent amount of money on cables.

The net benefit in all of this was confidence. I am confident that my home system is appropriately wired and I feel like it sounds better (even though it may be a placebo effect). In the past year I have started making my own cables for my headphone setup as well as my car. Although they may not be as nice as my MIT or Tara Labs cables, I still have confidence because I know that I made them correctly and they are dependable.

My point is this: Even though the effects of all of this may be in my mind, I perceive a difference. It doesn't have to be expensive or from a well known brand. All the cables need to do is give me confidence that they are not my weak link.

Well said. Let's face it, a lot of us buy audio equipment for reasons other than pure sound output. Don't deny it folks, you've probably bought stuff based on looks before. If the cables make you feel better about your system for whatever reason (confidence, looks, organization, and so forth) then who's to say whether or not it's worth the extra money to you?

Having said that, it still seems as if a lot of people are insisting that RCA cables color the sound in the real sense. And I think that's what the thread is mostly focusing on.

[Thoraudio]

I don't know, the other night I was hanging out with my nephew and we found shape could have an impact on the sound. We had two mic's built of similar materials but in different shapes. With a GENUINE Dupont Micro-fiber interconnect we found a Campbell mic did provide descent results, but we preferred the more authoritative tone of the larger Progresso. How do you explain that with RLC? :rolleyes:

are you taling about microphone shapes? That's not an electrical component, it's physical, which can affect the sound... like the shape of a speaker.

[Autiophile]

Having said that, it still seems as if a lot of people are insisting that RCA cables color the sound in the real sense. And I think that's what the thread is mostly focusing on.


You're right, this is a thread about the science of cables. There have been several of these threads over the past few days and it seems to me that the whole argument is an issue of perception vs. scientific measurement. By simply focusing on RLC or measurable audible differences we leave out the most complex part of the system, our minds.

Over on Headfi.com we have gotten into discussions about the differences in the shapes of peoples ear canals and how they impact sound, to the point where many individuals have seperate level controls for Left and Right channels to provide compensation. Before I digress too far, my point is simply to remind everyone of the complex, multivariate, nature of perception.

Perhaps we all need therapists to tell us "You're system is well designed, well executed and sounds great. You are a good audiophile and you should feel good about yourself." (I'm willing to tell you this for a nominal charge ;) )

I haven't spoken to my understanding of the science here because I am an environmental engineer, not electrical, and I fear exposing my lack of knowledge. Not so much to you guys, but if my wife finds out that I don't know what I'm talking about I think my audio funding will get cut :( .

[Thoraudio]

don't let that stop you.... I'm a ChemE working in environmental. Doesn't keep me from pretending I know what I'm talking about.

[MIAaron]

I apologize Thor, I failed to get my point across. Please dont read any more into my post as it was a bad joke. I gotta say you gave a good answer though, cuz in the context of my post physical traits are the only ones that matter.

[DS-21]

You're right, this is a thread about the science of cables.

Were that actually the case, it would be nothing but blank posts.

[chad]

I apologize Thor, I failed to get my point across. Please dont read any more into my post as it was a bad joke. I gotta say you gave a good answer though, cuz in the context of my post physical traits are the only ones that matter.


I got it..... but it took me a second of going.... Hu, um... Oh hell, he's pulling my leg :D

Chad

[DS-21]

there is something to be said for perception.

There is also something to be said for efficient allocation of resources. If people who obsess about wires channeled that energy and cash into fine-tuning speaker placement by measurement and ear, optimizing their listening rooms, etc., the bottom line is that they would have objectively more accurate (not necessarily better-sounding, of course, but probably so) systems.

It's an upside-down hobby indeed when people whine about wires whilst listening to speakers that are so poorly engineered that their designers did not even bother to maintain smooth and relatively constant directivity over the midrange and treble.

[MIAaron]

I got it..... but it took me a second of going.... Hu, um... Oh hell, he's pulling my leg :D

Chad

Is Mr. Sound Engineer baggin' on my Campbell mic? :D ;) We had'em networked man, from one couch cushion fort to the next. :)

[werewolf]

Man these threads always go the same way ... the only mystery in the realm of cables may just be, why i never seem to learn :(

But I will respond to the comments and questions posted by Wes :)

Yes, it's funny to me to think that the three (3) great mysteries of modern science are :

1. A unified field theory that accurately explains gravity, electromagnetism, strong & weak nuclear forces ... thereby unifying quantum mechanics and general relativity.

2. The existence of dark matter and dark energy, which seem to cause to rate of expansion of the universe to be increasing ... beyond all expectation.

3. How the hell to get a 20kHz electrical signal down a few feet of wire.

But anyway ... let's take a moment to address the question about how the cable may impact electrical, and therefore ultimately acoustic, phase. The first, and only, rule in "cable engineering" is : how do any claimed or advertised "properties" impact RLC? Resistance, Inductance and Capacitance are ALL you need to be concerned with (putting aside, for the moment, contact metallurgy and noise immunity). These well-established electrical properties are the "filter" (if i may) through which any crazy geometry or elixir claims should be passed. Why? Very simple : if something doesn't impact RLC, it won't impact the transmission of a 20kHz signal through a cable less than about a mile long. This is, unfortunately for some, not subject to opinion or experience. If your subjective experience suggests otherwise, you have been fooled (fret not, though, it happens all the time). Ignoring this simple fact, demonstrates a fundamental ignorance about electrical engineering and the work done by brilliant minds for centuries concerning electrical theory. RLC concepts have become SO powerful in modelling, explaining and predicting the universe around us, that they are also used in mechanical and acoustical sytems as well. Don't believe me? Too bad.

Once again ... I am NOT suggesting that all cables sound the same. That's an hypothesis that would be ridiculously easy to disprove. I am, however, suggesting ... or rather, stating as factual with the same confidence that the earth will continue to rotate tomorrow ... that any sonic differences are attributable to RLC analysis (contact metallurgy and noise immunity aside).

OK ... so let's look at an exaggerated, but not outside-the-realm-of-possibility, example. Say we've got an RCA cable with a (high) capacitance of 40pF per foot. And we are driving 50 feet of that cable from a (high) source impedance of 1kohm. Let's ignore any series resistance (R) in the cable (it will be much less than the 1kohm source), and we'll also put aside any series inductance (L) for now. We'll just concern ourselves with C. We'll also assume that the amplifier on the receiving end has a very high input impedance, much higher than the 1kohm source, so we can ignore that as well.

In this case, it's very easy to show that the source resistance and cable capacitance form a simple, first-order RC low-pass filter. This does NOT mean that anytime a resistor and capcitor are in a circuit, that a simple first order low-pass is formed. It is so in this case, because the source resitance is a series resistor and the cable capacitance is a shunt capacitor, and the output is observed across the shunt capacitor.

The cutoff or -3dB frequency of this low-pass filter is :

f3db = 1/(2*pi*R*C) = 1/(2pi*1kohm*40pf/ft*50ft) = 80kHz

Next post we'll show how an 80kHz low-pass filter impacts magnitude ... and phase ... of a 20kHz signal. What other "electrical properties" of the 20kHz signal might be impacted? That's simple : NONE. Why? Because there AREN'T any ... not in a linear system. And it's a no-brainer to consider a cable to be a linear system ... by far, wire is the most linear of electrical components we have to worry about in storing, transmitting and reproducing acoustical information.

What about time-domain properties like transient response? Isn't that something to worry about? Why yes it is (or may be) ... glad you asked :) But we've already got you covered ... completely, in fact. ANY and ALL time domain properties are UNIQUELY linked to frequency domain MAGNITUDE and PHASE. ALL time domain properties are uniquely and completely dependent on what happens in the frequency domain (considering both magnitude and phase). This means that ALL time domain behavior is 100% accurately predictable if you know the frequency domain behvior. And it also means that you can't have two circuits which behave identically in the frequency domain, but differently in the time domain. Never gonna happen ... it's been proven, with the certainty of a theorem ... and there is no stronger PROOF in all of human experience. Yeah ... it a was french dude who did it (Fourier), but he was right nonetheless ;)

[chuyler1]

Excluding the connectors, if all of the properties of cables actually do have an affect on sound, wouldn't that mean that the internal amplifier wires and circuit board material would also have an affect on sound? Do amplifier manufacturers pay the same close attention to the materials they use as the cable manufacturers?

Or does the length of the cable affect the sound and that is why the materials used matter so much?

[werewolf]

quick answer ... look how long the above cable had to be (and at a rather high capacitance per foot, too), in order to get a -3dB cutoff frequency as low as 80kHz :)

So, no ... amplifier manufacturers don't really need to worry about what type of wire they use :) except, of course, heavy enough gauge for the current and power delivery.

They have other things to worry about, however. Stability concerns certainly force one to look into the several hundred kilohertz, or even megahertz range, for interesting signal dynamics, for example. But all that is a topic for another thread :)

[MarkZ]

You're right, this is a thread about the science of cables. There have been several of these threads over the past few days and it seems to me that the whole argument is an issue of perception vs. scientific measurement. By simply focusing on RLC or measurable audible differences we leave out the most complex part of the system, our minds.

Over on Headfi.com we have gotten into discussions about the differences in the shapes of peoples ear canals and how they impact sound, to the point where many individuals have seperate level controls for Left and Right channels to provide compensation. Before I digress too far, my point is simply to remind everyone of the complex, multivariate, nature of perception.

But you also have to keep in mind (no pun intended) that the brain makes an attempt to compensate for the early transduction mechanisms that may give rise to odd FR/phase behaviors. So ear issues, as long as they're not rapidly dynamic (eg. ear wax, eustachian tube dysfunction, sudden hearing loss, etc), are for the most part taken care of by the brain. That is, the shape of the ear canal and the pinna and the significant variation in the bones that underlie the transduction don't play much of a role in the end, because the brain has already addressed it.

So that no confusion arises, I should qualify that statement with this -- the brain can only process that information that's available to it. So when werewolf talks about the shape of the pinnae impacting vertical cues, it's something that the brain CAN'T compensate for because those cues are not physically present otherwise. It's not information that a simple gain control mechanism (something the brain is very good at) can account for.

[Thoraudio]

Just a few more questions.

Wasn't there some rumblings this past year about the upper limit for supernova energy expulsion (the chandra sakkar or something)? Wasn't that fundamentally questioned and doesn't that affect the dark matter and dark energy theories?

and in a DS-21 like turn.... doesn't Dark matter/energy prove that there may be something goin on in wires and amps? we don't know what it is, but we know it's there ;)

[werewolf]

Wes = smartipants :p

I'll answer a question with another question : when we discovered that the orbit of the planet Mercury simply did not seem to follow that predicted by Newtonian Dynamics, were we all afraid that our bridges would start collapsing?

:)

[MarkZ]

Man these threads always go the same way ... the only mystery in the realm of cables may just be, why i never seem to learn :(

Difficult to resist, huh?

2. The existence of dark matter and dark energy, which seem to cause to rate of expansion of the universe to be increasing ... beyond all expectation.

You know there's a problem when physicists have resorted to create names for ficticious "stuff" in an attempt to explain away nonlinearities that really shouldn't be all that unexpected in a nonlinear universe. That A+B don't equal C does not necessarily mean that there's a missing term on the left side of the equation. It could simply mean that the operator is wrong. Basically, I consider the whole thing to be a problem that only points out that we don't know everything there is to know about how the universe operates, rather than the notion that we're missing components. Which is why the whole notion of "dark matter" and "dark energy" are terribly misleading.

Once again ... I am NOT suggesting that all cables sound the same. That's an hypothesis that would be ridiculously easy to disprove. I am, however, suggesting ... or rather, stating as factual with the same confidence that the earth will continue to rotate tomorrow ... that any sonic differences are attributable to RLC analysis (contact metallurgy and noise immunity aside).

I think you're giving in too much, werewolf. All but the most esoteric designs (which are probably also the most expensive) will provide virtually zero perceptible effects by virtue of the sound alone. And when you take into account the imperfections inherent in a car, any measurable effects will be completely swamped.

[Thoraudio]

no, but I'd say our grasp on dark energy, dark matter, strings and such, is much less concrete than the formative grasp on newtonian physics.

But I digress.... back to wire bashing.

On the subject of speaker wires and weak links.... what's the purpose of silver wires when (for home speakers), the binding posts, the internal wires, coils in xovers, crossover circuit boards, and VC's are copper. And the solder is made from tin/lead....

what if *gasp* the vc is made out of aluminum.... (((shudder)))

[T-Ro]

So who is going to write up the tutorial on "How to build Custom RCA's to maximize the RLC performance of your signal path"? Or, "How to time align your system by modifying the signal cable."

Does equipment that can measure RLC accurately enough for the purposes of tweaking RCA construction even in the realm of possibility for the average DIYer, cost wise that is?

If I knew how to properly measure RLC of the cable / source / amp system, what the heck I was looking at and how it affected the sound I'd build some cables. It would be a neat experiment to build cable with different wire and see if the preceived changes in sound match up with expectation from the scientific data.

I can see it now... Neutrik Connectors with Canare instrument cable from the head unit to the eq. Canare RG-6 connectors with Belden Coax from EQ to XVR, a Stinger RCA to the Tweeter amp (got lucky), Mogami twisted pair and Echimman (sp?) to the mid amp, Starquad with Parts Express special RCA to MB and Soundcraft RCAs with hand braided sliver wire to the sub (for that magical bass extension, but all scientifically proven of course). Then you buy a new crossover and you have to start all over. AHHHGGGG...

Anyway, I really don't need another thing to have to tweak, but it would make me feel really smart to know how to measure and modifiy a cable to change the response of my system.

Thanks for bringing the technical knowhow Werewolf. You are making me want to go get out my old text book from the one EE class I took in college.

[MarkZ]

If I knew how to properly measure RLC of the cable / source / amp system, what the heck I was looking at and how it affected the sound I'd build some cables. It would be a neat experiment to build cable with different wire and see if the preceived changes in sound match up with expectation from the scientific data.

That was done 25 years ago and published in the J.AES, at least for speaker wires (whose potential sonic benefits should far outweigh RCA cables due to the much lower impedance load). Fred Davis was the author. If I recall, he even included in his test group a set of jumper cables he had lying around...

[werewolf]

Mark's point is VERY well taken ... and helps to address the above post.

I have stated that the signal transmission can't be impacted unless RLC is impacted. Very true. However, this does not mean that any difference in RLC is audible. And it does not mean we should be on an eternal quest to minimize RLC.

A few cases-in-point :

1. Imagine an RCA cable connecting a preamp, with source impedance of say 200ohms, to an amplifier, with input impedance of say 10kohm. How much should I worry about reducing cable resistance from 2ohms to 1ohm?

2. In my above example (which I still need to finish), we saw a VERY long RCA cable introduce a low-pass at 80kHz. How much should I worry about improving that to 160kHz? Or 320kHz?

[werewolf]

OK ... how does an 80kHz first-order lowpass impact phase in the audio band?

Here's the Transfer Function (derived by simple voltage division):

Vout/Vin = [1/jwC]/[R + 1/jwC] = 1/(1 + jwRC)

where w=radian frequency=2*pi*f, R=1k, C=50ft*40pF/ft=2000pF

In general, a Transfer Function is a complex function of frequency, which really just means that the frequency response has two parts : a magnitude function vs. frequency (often erroneously equated with frequency response in audio), and a phase function vs. frequency. All we need to do is find the magnitude and phase of a complex "number" ... or function of frequency, in this case :)

The Magnitude Response is :

|Vout/Vin| (in dB) = 10*log{1/[1 + (wRC)^2]}

somebody can tell me the magnitude response at f=10kHz, 20kHz, 40kHz, 80kHz, 160kHz, 320kHz :)

The Phase Response is :

Angle[Vout/Vin] = -arctan{wRC}

somebody can tell me the phase response at f=10kHz, 20kHz, 40kHz, 80kHz, 160kHz, 320kHz ... and in so doing, answer the question : what does the phase response of a first-order low-pass filter look like? :)

[Tommythecat]

We could simply ask what affect phase has in the audio band as well - and bypass your little homework assignment.

Which is audible, but not disagreeable.

[werewolf]

Absolute Phase : audibility is debatable ... but at some point it certainly is audible, as easily demonstrated by looking at extreme values of group delay.

Relative Phase : quite audible, as it impacts how one driver interacts with another acoustically (be it the corresponding driver on the other channel, or another driver on the same channel at crossover)

Once again, I'm not arguing in favor of cable sonics :) Just answering a question posted. No need to consider the homework if disinterested :D

[Thoraudio]

-221? Imma double check my numbers.
-90

[werewolf]

This is the Magnitude and Phase Response of the first-order low-pass filter formed by the cable capacitance & source resistance described above :


FREQUENCY.....MAGNITUDE........PHASE

10kHz.................-0.068dB........-7.2 degrees

20kHz.................-0.27dB..........-14 degrees

40kHz.................-0.98dB..........-27 degrees

80kHz.................-3.0dB............-45 degrees

160kHz................-7.0dB...........-64 degees

320kHz................-12dB............-76 degrees

640kHz................-18dB............-83 degrees

Conclusions :

- The magnitude response should look familiar : -3dB at 80kHz, asymptotically approaching a 6dB/octave rolloff as frequency increases.

- The phase response always seems to be a point of confusion ... there is no single number for the phase of a filter : -45 degrees at 80kHz, asymptotically approaching -90 degrees as frequency increases.

- Even in this artificially exaggerated case, the audio band impact ... including both magnitude and phase ... is minimal.

- Is this the response for any RCA cable? Of course not! Will it be different for a different source resistance? Yes. Will it be different for a different cable, of different length and capacitance? Yes. Can the techniques presented here be used to calculate the possible (but unlikely) audio band impact of any RCA cable? YES :)

[AVI]

Werewolf ...... You've blinded me with science !

I mean , doesn't your head like ...hurt ? LOL :D

[werewolf]

Science (and logic, to Mark's point) will not blind you ... in fact, quite the opposite :)

It's the light of a best friend, for navigating your way through the dark world of audio bullshit :D

[AVI]

Science (and logic, to Mark's point) will not blind you ... in fact, quite the opposite :)

It's the light of a best friend, for navigating your way through the dark world of audio bullshit :D
I'm afraid that mankind's superior belief that they can expain EVERYTHING in this life through science and logic , is sorely flawed when it comes to music. Production , reproduction , ect .... Music is an emotional experience way beyond the Ones and Zeros , bits and bytes. And it is a VERY narrow view for one to think they can explain everything with technical explanations.
A HUGE part of listening to music is experiencing the emotions it brings to an individual , and if a part of THAT experience is influenced by a percieved joy due to owing an individual's cable of choice , NO AMOUNT of math or technical explanation can ever help ... but instead only serve to dampen the joy of experiencing music itself.
I feel sorry for narrow and close minded individuals who thinks everything sounds the same , due to some math ....

[MarkZ]

I'm afraid that mankind's superior belief that they can expain EVERYTHING in this life through science and logic , is sorely flawed when it comes to music. Production , reproduction , ect .... Music is an emotional experience way beyond the Ones and Zeros , bits and bytes. And it is a VERY narrow view for one to think they can explain everything with technical explanations.A HUGE part of listening to music is experiencing the emotions it brings to an individual , and if a part of THAT experience is influenced by a percieved joy due to owing an individual's cable of choice , NO AMOUNT of math or technical explanation can ever help ... but instead only serve to dampen the joy of experiencing music itself.
I feel sorry for narrow and close minded individuals who thinks everything sounds the same , due to some math ....

The brain, in all its complexity, can't act on information that isn't there. Unless you're suggesting that there's some unaccounted for force at play that's yet to be discovered, then you must recognize that the only media that is responsible for the music is in the electrical realm. That is, the information originates on the CD and has to make its way to the brain -- so the earliest stage is electrical, and if it can be shown that the two electrical signals are identical then the logical conclusion is that the brain has the same information available to it in both cases. So the task, then, is clearly to demonstrate that the two electrical signals are the same. This has been done.

So the question isn't whether or not you enjoy it with the new cables. If that makes the experience more enjoyable to you, nobody's telling you not to do it. But recognize that, for those who aren't influenced by such superficial things, that "upgrade" serves no purpose but to drain the wallet and distract from potential upgrades that could generate a REAL influence (ie. physically manifested in the sound wave).

Edit: to clarify my first sentence, when I refer to "information" I'm talking about the external stimulus. The internal representation of that stimulus can of course change. It appears you're saying that your brain processes that information differently with the knowledge that the special cables are present. That's not unreasonable.

But while I'm at it, I should point out that there isn't a breakdown in logic, as you suggested in your post. Everyone in this thread so far has acknowledged that the brain uses a number of different cues to form the experience. In fact, that's been my point all along (and I assume werewolf's too) -- these very cues need to be eliminated when the question comes up as to whether or not the cables themselves contribute to a perceived difference in sound.

[DeLander]

What the HELL happened to Pluto?????

[werewolf]

AVI ... you've made a very fundamental error. You're confusing the electrical/mechanical/acoustical reproduction of music, with the human enjoyment of music.

Reproduction lends itself completely, totally and thoroughly to science and logic ... and emotion has nothing to do with it. The ACCURACY of reproduction is completely determined by ... "numbers".

Furthermore, the mathematical description of the universe is not a "belief system", whose accuracy is open to interpretation. The universe under the scientific method is, afterall, objectively testable.

Now the other category is enjoyment of music. And enjoyment is, I'll grant, an emotional experience. We certainly don't know everything yet about the chemistry of emotion ... but i sure wouldn't bet against science in this category for very long either ;)

[werewolf]

To further illustrate my point ... if two cables present identical voltages to loudspeakers, the loudspeakers have no choice but to create identical acoustical outputs. One may choose to believe otherwise, of course, but unfortunately logic reigns supreme.

Perhaps one gives a better "emotional enjoyment" ... particularly obvious, of course, when variables are not properly isolated ;) As Mark stated ... nobody is trying to prohibit your belief system ... especially the cable manufacturers and salesmen !! :D

[werewolf]

Something else I remembered, in the category of "comprehensive RLC modelling".

The new buzzword among megabuck cable suppliers seems to be "energy storage". Now ... isn't THIS outside the realm of RLC modelling?

The answer is absolutely NO. The capacitance (C) in the electrical model is the element we use to represent electrical energy storage. The inductance (L) in the electrical model is the element we use to represent magnetic energy storage. So ... all forms of electromagnetic energy storage are already completely comprehended in the RLC model we have been discussing :)

And no, you can't have two cables with identical frequency responses but different "energy storage." Sorry ... have to look elsewhere to support crazy claims.

Bottom Line : Until cable manufacturers start claiming gravitational effects in their cable sonics, we've got a pretty comprehensive description ;)

[cotdt]

it might just be RLC, but saying that is very misleading, because the resistance of the cable changes with the frequency. at high frequencies, the resistance rises and can be significantly high, looks like the impedance curve of a speaker. certain techniques like teflon coating reduces high frequency impedance which is why DIY CAT5 cables sound better.

also, i know for a fact that cable shielding also matters. i can put my finger near the cable and get static noises.

[werewolf]

maybe you missed the several times in this thread where I included noise immunity/shielding as an important property as well?

[MarkZ]

it might just be RLC, but saying that is very misleading, because the resistance of the cable changes with the frequency. at high frequencies, the resistance rises and can be significantly high, looks like the impedance curve of a speaker. certain techniques like teflon coating reduces high frequency impedance which is why DIY CAT5 cables sound better.

Resistance does not significantly rise with frequency. The way I define "significantly", it would have to come somewhere close to the several kilohm input impedance of the amplifier. But it doesn't. It'll add only a couple ohms. No one would call that significant.

Besides, like I said elsewhere, the easiest and cheapest way to combat the skin effect is by increasing wire gauge (thereby increasing surface area), not by implementing special new strand/dielectric properties or cable geometries.

[cotdt]

maybe you missed the several times in this thread where I included noise immunity/shielding as an important property as well?

I read this entire thread and didn't notice you mentioning shielding at all, so I had to mention it.

The expensive cables have different RLC values as compared to cheap radio shack cables, so I wouldn't be surprised if people hear differences. if i remember correctly, they have lower L and C, but slightly higher R than cheap cables.

The larger debate here is measurements versus hearing. There are those who claim that all cables, all sources, all decent speakers, and all amplifiers sound exactly the same, and they use (flawed) blind tests to prove it, and somehow the results agree with them. Yet to me the difference is like night and day. Usually I can both hear and measure a difference, but not always. In the case of amps and sources, it is not easy to measure since the response is almost always flat even with terrible-sounding equipment, and distortion is also low. Linear and nonlinear distortion entirely influences the sound and nothing else, this is the theory and I'm not disputing that. Nevertheless, with more sophisticated measuring equipment, people find that often there is indeed a measurable difference just like their ears have told them long ago. For example, you can have two speakers both EQed to flat response, and both have distortion below audibility. Let's say one is a magnesium cone, and the other is a sliced paper cone. However, the difference between the two drivers is easy to hear because the two cones have different timbre. This means they have very different local frequency response but you need a very high resolution frequency response measurement, so this is a case where we can't measure it but in theory it's measurable. I think it's similar with other audio things like amps and sources. We hear the difference but the differences are not easy to measure, so this is why I put hearing over measurements.

[cotdt]

Resistance does not significantly rise with frequency. The way I define "significantly", it would have to come somewhere close to the several kilohm input impedance of the amplifier. But it doesn't. It'll add only a couple ohms. No one would call that significant.

Besides, like I said elsewhere, the easiest and cheapest way to combat the skin effect is by increasing wire gauge (thereby increasing surface area), not by implementing special new strand/dielectric properties or cable geometries.

why does it have to be several kilohms to be significant? in the measurements i've seen, some cables had over 20 ohms resistance at 20kHz. besides, we're not just talking about speaker cables but also other cables like interconnects where a difference would be more audibly significant.

[NaamanF]

I feel sorry for narrow and close minded individuals who thinks everything sounds the same , due to some math ....
A fool and his money are soon departed.

[MarkZ]

I read this entire thread and didn't notice you mentioning shielding at all, so I had to mention it.

The expensive cables have different RLC values as compared to cheap radio shack cables, so I wouldn't be surprised if people hear differences. if i remember correctly, they have lower L and C, but slightly higher R than cheap cables.

This is where the Fred Davis paper becomes really handy. He did just this experiment by looking at R, L, and C of a handful of cables. One thing you often find is that, due to the typical methods to reduce L and C, you often have a reduction in L but rise in C for some cables, and vice versa for the others. But again, it's important to mention that the Davis paper looked at speaker cables. The reason he looked at those was because speaker cables go in low impedance circuits. R, L, and C in RCA cables is so incredibly low compared to the load impedance that it's insane to even think that differences in R, L, and C could have any impact whatsoever. To be perfectly frank, anyone who thinks that it does clearly has no knowledge of the basics of circuit theory, really making them not equipped to even engage in the debate.

Anyway, I can provide the Davis paper in pdf form to those interested in seeing the data.

The larger debate here is measurements versus hearing. There are those who claim that all cables, all sources, all decent speakers, and all amplifiers sound exactly the same, and they use (flawed) blind tests to prove it, and somehow the results agree with them. Yet to me the difference is like night and day. Usually I can both hear and measure a difference, but not always. In the case of amps and sources, it is not easy to measure since the response is almost always flat even with terrible-sounding equipment, and distortion is also low. Linear and nonlinear distortion entirely influences the sound and nothing else, this is the theory and I'm not disputing that. Nevertheless, with more sophisticated measuring equipment, people find that often there is indeed a measurable difference just like their ears have told them long ago. For example, you can have two speakers both EQed to flat response, and both have distortion below audibility. Let's say one is a magnesium cone, and the other is a sliced paper cone. However, the difference between the two drivers is easy to hear because the two cones have different timbre. This means they have very different local frequency response but you need a very high resolution frequency response measurement, so this is a case where we can't measure it but in theory it's measurable. I think it's similar with other audio things like amps and sources. We hear the difference but the differences are not easy to measure, so this is why I put hearing over measurements.

What makes you think that distortion and frequency response can't be measured with even the cheapest instrumentation? Even my cheap sound card has far better resolution than any human's auditory system.

[werewolf]

Check my very first post in this thread, you'll see shielding mentioned. And it's not the only post.

Speakers are more complicated to measure than electronics, for a couple reasons :

- There is the added "dimension" (actually, 3 of them) of space.
- They distort more than just about any piece of electronics in the chain ... at levels significantly above hearing thresholds ... so comprehensive measurements of distortion are also required.

Doesn't mean that science doesn't have the tools necessary to measure what loudspeakers do to the air between them and your ears ;)

RCA cable resistance will matter MUCH, MUCH less than loudspeaker cable resistance, because the load (amplifier input, on the order of 10kohms) is about three orders of magnitude higher than a typical loudspeaker.

Double-blind testing of cables has demonstrated what science and logic dictate ... there is no audible difference in cables that can't be attributed to what logic and valid engineering demonstrate.

[MarkZ]

why does it have to be several kilohms to be significant?

Because that's what the load impedance is. Do you know what a voltage divider is?

in the measurements i've seen, some cables had over 20 ohms resistance at 20kHz.

Yikes! Which cables were those??

Even so, 20 ohms with a 5kohm input impedance amounts to only about .01dB.

besides, we're not just talking about speaker cables but also other cables like interconnects where a difference would be more audibly significant.

Actually, quite the opposite is true. I thought you were talking about interconnects at first, hence my use of 5kohm as a load impedance value. With speaker cables, the difference is more realizable since it's a lower impedance circuit. But even with that, resistance DIFFERENCES in cables are insignificant. And the best way to combat them (better than all other elaborate methods) is to just increase wire gauge.

[werewolf]

actually cotdt ... i mentioned noise shielding twice in my very first post in this thread ... did you even read it?

[mikechec9]

http://www.theaudiocritic.com/downloads/article_1.pdf

Interesting that The Cable Lie is #1 :rolleyes:

[AVI]

Here's what I know for POSITIVE ....

http://www.diymobileaudio.com/forum/showthread.php?t=7513

Electrical measurements can NOT explain results like this ... Logic and specs go right out the window ;)

[werewolf]

There is nothing about audio signal transfer over cables that is not understood by electrical theory. There is no "mysterious" aspect of low frequency current flow through conductors, that cable salesmen understand ... but electrical engineers do not.

If what you heard is indeed real, it is absolutely explainable by the electrical laws described in this thread.

Why do you believe otherwise? Even if what you heard is real ... and I'm not convinced one way or the other ... why are you convinced it is somehow "beyond" electrical theory to explain it?

Were all RLC, shielding, and metallurgy properties of the cables comprehended? That's the only way to be convinced that real sonic differences must be "beyond" these properties.

Even if I grant that what you heard is real ... why be so convinced that electrical engineering can't explain what you heard?

[werewolf]

allow me to elaborate AVI ... i'm really not trying to pick on you :)

Let's say that two cables to be compared are inserted into a system. The frequency responses ... including magnitude and phase over the audio band ... are measured in each instance. The measured responses are found to be virtually identical ... meaning, less than 0.1dB/1 degree at any frequency measured. A double-blind test is administered, where neither test administrator nor subject know which cable is being tested. No other variables are changed during the test ... including warm-up or power line fluctuations of electronics, break-in of speakers, building AC system switching on during one cable but not the other (possibly causing electrical or acoustical noise as well as power line fluctuations), etc. {Sound crazy? Sound overly anal? Welcome to the exacting world of the scientific method :)}

Sure enough ... a statistically meaningful difference is recorded, that can not be explained by random chance.

In this case, one may readily conclude that RLC aspects of cables ... which give rise to measurable cable frequency responses, as described in this thread ... do not explain all there is to know about "cable sonics." In other words, ONLY once all known effects are eliminated, may one conclude that some mysterious "unknown" is the cause.

[T3mpest]

Here's what I know for POSITIVE ....

http://www.diymobileaudio.com/forum/showthread.php?t=7513

Electrical measurements can NOT explain results like this ... Logic and specs go right out the window ;)
Why can't logic and specs explain that, because you don't like them too? Werewolf isn't saying that there is no difference in cables, or that you didn't hear what you heard, he's saying if you DID hear it, the differences can be measured, and explained, through 3 different "specs" of the cable in question. He's saying if there were F/R anamolies present, it was due to the length, resistance or capaticance change from cable to cable Not due to the cable geometry or other "high tech cable breakthrough". If spending $75 a foot for cable makes you feel better about yourself and your system, go ahead. If that's what it takes to allow you to really listen to your music and enjoy it then you may as well. While it may not make an actual difference, over a cheaper cable that's properly shielded with simlilar LRC values, if it gives you the incintive to listen for the low level details then why not? The human minds funny like that, it really can make 2 things that are EXACTLY the same, be percieved as different. Peace of minds worth something too, and if you really believe a more expensive cable has something to offer, you may never be pleased with anything less, regardless of how it actually sounds vs a cheaper cable. However, not everyone has enough money to spend on hyper expensive cables, so for them, knowing that a less expesive cables with similar RLC values will sound the same, geometry be damned, is important. There is one more thing I like to add, hopefully avi does read this, I think he may appreciate it. I believe I've used this quote before in a similar theread, and I think I'll use it again, this thread is asking for it even more.

"It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it not stirring to understand how the world actually works — that white light is made of colors, that color is the way we perceive the wavelengths of light, that transparent air reflects light, that in so doing it discriminates among the waves, and that the sky is blue for the same reason that the sunset is red? It does no harm to the romance of the sunset to know a little bit about it."

[AVI]

Ok Guys ... I misunderstood what your previous posts in this thread were driving at. That's my mistake.
I truly wasn't trying to make a counterpoint for argument's sake.
Werewolf , I believed you were driving at the point that RLC is the only thing that can make cables sound different , and that for the most part different cables would NOT have enough difference in RLC to actually hear ?
You can believe this : I'm a part of this forum to further my knowledge of all things audio ! Not to stir things up.
I knew that my experiences with blind testing were real , and thought your scientific points were saying that they could not actually be real.
My bad for mis-reading / mis-interpreting what you were saying.

Now that I understand better , that leads me to ask this :
What exactly makes it so that RLC can be so very different between cables , that actually does allow a person to hear differences sometimes ?

Is this where manufacturers simply get lost .... trying to explain the differences in simple RLC with " snake-oil " ? If so , why don't they just quote the differences is THEIR particular RLC make-up ?

[AVI]

Why can't logic and specs explain that, because you don't like them too? Werewolf isn't saying that there is no difference in cables, or that you didn't hear what you heard, he's saying if you DID hear it, the differences can be measured, and explained, through 3 different "specs" of the cable in question. He's saying if there were F/R anamolies present, it was due to the length, resistance or capaticance change from cable to cable Not due to the cable geometry or other "high tech cable breakthrough". If spending $75 a foot for cable makes you feel better about yourself and your system, go ahead. If that's what it takes to allow you to really listen to your music and enjoy it then you may as well. While it may not make an actual difference, over a cheaper cable that's properly shielded with simlilar LRC values, if it gives you the incintive to listen for the low level details then why not? The human minds funny like that, it really can make 2 things that are EXACTLY the same, be percieved as different. Peace of minds worth something too, and if you really believe a more expensive cable has something to offer, you may never be pleased with anything less, regardless of how it actually sounds vs a cheaper cable. However, not everyone has enough money to spend on hyper expensive cables, so for them, knowing that a less expesive cables with similar RLC values will sound the same, geometry be damned, is important. There is one more thing I like to add, hopefully avi does read this, I think he may appreciate it. I believe I've used this quote before in a similar theread, and I think I'll use it again, this thread is asking for it even more.

"It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it not stirring to understand how the world actually works — that white light is made of colors, that color is the way we perceive the wavelengths of light, that transparent air reflects light, that in so doing it discriminates among the waves, and that the sky is blue for the same reason that the sunset is red? It does no harm to the romance of the sunset to know a little bit about it."Thank you for the tasteful and helpful post.
Please understand , that if i seem defensive , it is due to previous discussions over the years with scientists I have had. MANY of these insisted my experiences with my in-depth blind testing was pure BS , and that under NO circumstances can ANY human EVER hear a difference with different cables ...... This was basically like calling me a fool and a liar .... THAT will tend to make a person defensive , especially when he only has his personal experience to draw from , and not a 170 IQ ;)

[lbridges]

....If so , why don't they just quote the differences is THEIR particular RLC make-up ?

Because they couldn't justify the price charged on that basis.

[fej]

Cool thread. Thanks Mark Z and Werewolf for the scientific breakdown. Always "felt" that expensive cables did not "improve" the sound, and now I understand the science behind that feeling. I have always spent a little extra money for quality connects and shielding, but never anything crazy. Same reason I never spend a ton of money on speaker cable. Rather have something more important .. like more watts ;)

[MarkZ]

MANY of these insisted my experiences with my in-depth blind testing was pure BS

They may very well be. You didn't describe your testing paradigm in detail. "Blind testing" is not exactly trivial...

and that under NO circumstances can ANY human EVER hear a difference with different cables ...... This was basically like calling me a fool and a liar .... THAT will tend to make a person defensive , especially when he only has his personal experience to draw from , and not a 170 IQ ;)

No one is calling anyone a fool or a liar. I think everyone is being completely forthcoming in this discussion.

[NaamanF]

MANY of these insisted my experiences with my in-depth blind testing was pure BS , and that under NO circumstances can ANY human EVER hear a difference with different cables ...... This was basically like calling me a fool and a liar

I think the only time people would consider a person a fool or a liar is if they based the differences in SQ of cables based on the fact that they have Teflon coated Egyptian cotton dielectric wrapped around buckyball carbon nanotubes filled with ferofluid that has been cryogenicly frozen in a anechoic chamber, twice. And they believe the cables sound better from this even though they measure the same as a $1 radio shack cable.

The way I pretty much sum this all up is if the cables measure the same in respect to RCL, they will sound the same. Price not a factor ;)

[T3mpest]

Thank you for the tasteful and helpful post.
Please understand , that if i seem defensive , it is due to previous discussions over the years with scientists I have had. MANY of these insisted my experiences with my in-depth blind testing was pure BS , and that under NO circumstances can ANY human EVER hear a difference with different cables ...... This was basically like calling me a fool and a liar .... THAT will tend to make a person defensive , especially when he only has his personal experience to draw from , and not a 170 IQ ;)

No problem, it happens. Anyway, most manufactures claim other things matter to help boost sales. If the average consumer was a engineer, they'd know that cable geometry doesn't matter. And that no 100 page tech paper was going to change the VERY simple laws that govern electicity flowing through a wire. They'd know that honestly, musical singals aren't that complex, and don't require any hyper special cable treatments to be sent across a cable accuractely. The average consumer, however, isn't an engineer. If they are paying 20x the price of a el cheapo cable, they need justification. If that means the cable company pays actual engineers lots of money to use "pseudo science" to create a "superior" cable, then so be it. If they can minimize lower the "skin effect" from 1000x below the threshold of human hearing to 1000000x below the threshold, then so be it. They have to justify the price of the cable to an audiophile, and if that means making stuff up, then so be it. Using actual electrical theory makes cables too simple, just by measuring 3 specs of a wire, any decently designed wire can be compared vs one another easily, it's too hard to raise the price that much when only 3 little numbers change each time.

[werewolf]

A quick summary of my views on audio cables, for what it's worth ...

If someone says, "I can hear a difference in cables." I find that statement very un-interesting.

HOWEVER, if someone states the following :

"After a well-controlled test where all other possible variables were eliminated, a statistically significant result demonstrated, logically and conclusively, that differences in cables were audible. Furthermore, the RLC properties (as well as contact metallurgy and noise shielding) were measured, and the differences were found to be below the threshold of human hearing."

Now THAT would be very interesting indeed!

But I have yet to hear that statement ...

[evan]

werewolf,
I feel kind of cheated that you didn't mention what you are using in your own system.

[solacedagony]

Thanks for the enlightening post Werewolf. Highly appreciated!

[demon2091tb]

Sure yall just don't wanna rub some snake oil on your wires, then go ahead and dump some on your towers as well, i'm sure that would make them look better as well as sound better.

Just don't leave it on the surface, you need to buff the hell out of it and get it deep deep down into the grain, mabey then it'll make a difference. :rolleyes:

I can honestly see why someone would say that there $50/ft sounds better than our $.25-$1/ft wires..........but does it really have precedient without measuremnts/etc.....nope. Until then i'll stick with my cheap wiring.

[Daishi]

Since "skin effect' is one of those items people bring up while talking about cables would someone mind explaining how this can actually play a role? I understand the idea that due to internal impedance the current is "pushed" to the outer areas of the cable, but this is only found in AC applications correct? I've heard people apply this to power cable, speaker cable, RCA's etc..and would like to know does it actually play a role, and if so on what cables is it most likely to crop up.

[Thoraudio]

1st. Skin effect doesn't have an audible affect at audio frequencies.

2nd. Skin effect works over uninsulated multistrand wires the same way it works over solid core. The only combat for this is Litz or Hyper-Litz wire, where every single strand is insulated.... but again, not an issue at audio frequencies.

[Daishi]

Thanks, that's what I figured. At what range does it play a role? above 20khz?

[werewolf]

Here's a good link on skin effect. It's a little math-intensive, but pages 2-5 give some good examples for audio (loudspeaker) cables :

http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/skineffect/page1.html

Figures 3 & 4 on page 2 are particularly "interesting."

And after a very thorough analysis of skin effect over the audio band, the conclusions (end of page 5) for loudspeaker cables are :

- use reasonably thick conductors to minimize resistance (R)
- use reasonably close spacing to minimize inductance (L)

how about that :)

[Daishi]

Thanks werewolf. I'll give that page a read and see if I remember any of my calculus ha.

[jtholley03]

Going to read this in full when I get a chance. I have balanced and unbalanced at home and in the car.

Hands down and simple for car audio: unshilded and unbalanced silver with minimal jacket.

I have LiveWire Solutions Direct Box black boxes which convert RCA to balanced and see absolutely no reason for this in the car with careful cable routing. If there is noise there converting to a balanced signal like some amps do then converting back takes away from the sound and adds way too many cables.

Shielding adds capacatince to the line and slows and dulls the sound.

Halfway careful routing of unshilded RCA gives awesome clean sound.

[cotdt]

well it seems like good arguments were given for the neglegible effects of resistance and capacitance in cables, so long as the values are not extreme. but i'm convinced that inductance is what is causing different cables to sound different.

"It has been demonstrated that low inductance is a desirable quality to have in a speaker cable due to the strong relationship between inductance and signal risetime. My source for this information was an article in the Winter of 1995 Audio Ideas Guide by a retired Bell Labs engineer named James H. Hayward. His conclusions were, simply put, the lower the inductance, the faster the risetime when using a cable in the amplifier/speaker interface. By using twisted pairs (with each wire within the pair used as opposite polarity), we keep the inductance to a minimum."

from http://www.venhaus1.com/diycatfivecables.html

Some trusted opinions say they hear a difference using CAT6 cables. I will try this out for myself and see. Maybe do a blind test on myself as well.

[MarkZ]

Rise time is pretty much just another way to say high frequency response, so the fact that inductance limits high frequency response is pretty basic. Just keep in mind that the things that might (and might is the key word) affect speaker cables aren't usually applicable to interconnects. As werewolf demonstrated, the impedance in the circuit before amplification is so high that you would need huge amounts of capacitance and inductance to get anywhere. Cables would be more likely to have an effect in very low impedance circuits (1 ohm, anybody?). And even then inductance is really only going to play a part with high frequency drivers, particularly tweeters.

[werewolf]

Another way to say what Mark just said ...

"Rise time" is absolutely NOT independent of frequency response. In fact, the two are completely correlated ... give me a first-order low-pass filter, tell me the cutoff frequency, and I'll tell you the rise time through that filter. No if's, and's or but's :)

If the bandwidth of the cable (including source and load) is significantly higher than 20kHz ... there will be no audible consequence of finite "rise time."

Alternatively, the ear's upper frequency limit of about 20kHz also places a limit on audible rise time.

"Rise time" and "frequency response" are two sides of the exact same coin. In fact, it's perfectly fine to consider them to be ... one and the same :)

[werewolf]

at the risk of beating this to death ...

You can't have two cables, each with a bandwidth of (or frequency response that extends to) 40kHz, for example, with different rise times. It's physically impossible.

Bottom line : if the inductance is low enough to cause the bandwidth (of the cable, source, load network) to extend well beyond 20kHz, then the rise time is absolutely fine by definition. No need to look for lower inductance to make rise time faster ... any more than you need to look for lower inductance to make the bandwidth wider.

[kevin k.]

Senor Lobo... ygpm :)

[cotdt]

I found something interesting:
"Different frequencies propagate at different velocities inside conductors since we're dealing with an electromagnetic signal. In air, sound waves travel at a constant regardless of frequency (this constant is affected by humidity, temperature and air pressure as a function of altitude and weather). Light too is an EM wave that travels through air and vacuum – as are radio waves. The different propagation speeds of different light are nicely displayed with a prism, showing that red light for example travels slower than blue light.

Audio signal propagation velocities are thus dependant on frequency. Naturally, different arrival times at the ear are counterproductive. Phase differences, transient delays and harmonic shifts undermine signal fidelity. And while there is an address to force coincident time arrival for all frequencies in a cable, it's not a given that all cable manufacturers incorporate it. Their products can then sound dull or slow, soft or harsh."

from an unlikely site, but this particular article is actually informative:
http://6moons.com/audioreviews/interconnects/interconnects.html

[werewolf]

The problem with that article is that it makes no mention of the varying orders of magnitude involved, and what's significant versus so tiny as to be impossible to perceive.

For example, it's easy to say that different frequencies propagate with different velocities, but it's completely meaningless without quantifying it. What if the different velocities mean a different arrival time between your subs and tweeters of ... 1 nanosecond? How might that be different than 1 microsecond? Or 1 millisecond?

The reality is, for standard cable lengths ... the effect is completely insignificant.

And without mention of orders of magnitude, or quantifying the effect, erroneous comparisons and conclusions are involved. The article goes on to say that this very effect was dealt with in telephone lines with the addition or management of inductance (which is an oversimplification of the effect of telephone line loading coils, by the way).

What's wrong with comparing an audio cable with a cross-country telephone line?

[werewolf]

... by the way, I've stated earlier that for audio cables less than a few miles long, a so-called "lumped analysis" is extremely accurate. This is, sadly for many, an undeniable fact.

And in that lumped analysis, I've stated that the RLC parameters are ALL that matters ... or, more accurately, all that COULD POSSIBLY matter.

And any RLC analysis that might possibly demonstrate any effect over the audio band will show a possible phase shift over that audio band. In fact, we demonstrated one, in an artifically exaggerated example in this very thread ;) And it just so happens that the first derivative of phase wrt frequency is something we call "group delay" ... and the group delay analysis will indicate any delay or arrival time differences for different frequencies :)

So the bottom line is this : if there are ANY significant "arrival time" differences at different frequencies, our friendly old RLC analysis will demonstrate them completely!! :)

Once again ... RLC is all there is to cables (not counting contact metallurgy and noise rejection). There is simply no other valid conclusion.

[t3sn4f2]

I have an older Orion 2150SX amp that I bought new and only used for a year back in 1996. Its been sitting in my closet for 10 years. I looked at the power cables the other day and found a sticky gunk residue threw out the entire lenght of both the + and - built in power wires, I've also seen this happen in my monster cable speaker cables that are around the same age, (the clear cased ones with the single conducter in the middle endcased in white plastic running threw them, ones from the 90s from sound advice, they were decently priced). On the other hand the speaker wires from the plug on the same amp were shinny and clean when I checked them. Is there a way of knowing which type of copper cable are more likely to have this happen to them and possbly affect the contact strenght.

I know alot of people say cable are ok as long as the connectors, soldering, and shielding are ok. But these cables I have are more then what bargain cable would be and they uuummm sucked. Are we doomed to paying more for cable then we have to just to avoid something that will affect performance like this problem I found.

[werewolf]

Please allow me to do, what I accused that most recent article of not doing ... namely, to quantify the effect of different delays at different frequencies :)

In our exaggerated cable example, we found that 50 feet of a highly capacitive cable (40pf per foot), driven by a high source impedance of 1kohm, gave us a low-pass cutoff of 80kHz.

And we calculated the phase of the first-order filter to be :

Phase = -arctan(wRC)

where w=radian frequency=2pi*f, R=1kohm, C=(40pf/ft)*50ft=2000pf

I've recently stated that group delay is :

Group Delay = - d/dw [Phase(w)] = RC/[1+(wRC)^2]

So we can caluclate the various group delays at different frequencies resulting from the analysis of our exaggerated cable:

10 Hz : 2.0000 microseconds
100Hz : 2.0000 microseconds
1kHz : 1.9997 microseconds
10kHz : 1.9689 microseconds
20kHz : 1.8812 microseconds

How can we judge the significance of a 120 nanosecond group delay difference between sub-bass and upper treble frequencies in our exaggerated cable example? One option would be to compare 120 nanoseconds to the time delay resolution in the most sophisticated audio processors available (like the new Alpine F#1). Alternatively, one could equate this time delay to a physical separation, based on the speed of sound (about 1100 feet per second). Or perhaps we could compare 120 nanoseconds to the hearing thresholds of group delay, presented here :

http://en.wikipedia.org/wiki/Group_delay

In any case, you'll find the different delays at different audio frequencies to be utterly insignificant, even in our highly exaggerated cable example :)

[cotdt]

Yes, I can agree that it is too little an effect to be significant. All in all, you guys seem to be saying that

1. R,L,C and shielding are the only factors that make a difference in cables.
2. Except for very extreme values, RLC doesn't effect the frequency response enough to matter.

So therefore one can still conclude that all cables sound the same, unless the connection contact is really poor, as noted by werewolf. But I don't understand why werewolf said that cables can sound different, if he also says that the resistance, capacitance, and inductance in typical cables are too low to matter. So, please clarify guys. Do all cables sound the same or not?

[squeak9798]

Yes, I can agree that it is too little an effect to be significant. All in all, you guys seem to be saying that

1. R,L,C and shielding are the only factors that make a difference in cables.
2. Except for very extreme values, RLC doesn't effect the frequency response enough to matter.

So therefore one can still conclude that all cables sound the same, unless the connection contact is really poor, as noted by werewolf. But I don't understand why werewolf said that cables can sound different, if he also says that the resistance, capacitance, and inductance in typical cables are too low to matter. So, please clarify guys. Do all cables sound the same or not?

He said it's not "impossible" for cables to sound different. The potential is there for cables to "sound" different. We can determine this potential by examining the RLC properties (aswell as noise rejection capabilities and contact metallurgy) to completely determine the ability, or lack thereof, for two cables to "sound different". And he later elluded that the RLC properties of a cable would have to be staggeringly out-of-the-ordinary to have any audible affect. So it's possible; Yes. But very highly unlikely to be from anything related to RLC.

[MarkZ]

Yes, I can agree that it is too little an effect to be significant. All in all, you guys seem to be saying that

1. R,L,C and shielding are the only factors that make a difference in cables.
2. Except for very extreme values, RLC doesn't effect the frequency response enough to matter.

So therefore one can still conclude that all cables sound the same, unless the connection contact is really poor, as noted by werewolf. But I don't understand why werewolf said that cables can sound different, if he also says that the resistance, capacitance, and inductance in typical cables are too low to matter. So, please clarify guys. Do all cables sound the same or not?

I believe werewolf is just being diplomatic. :D

[cotdt]

He said it's not "impossible" for cables to sound different. The potential is there for cables to "sound" different. We can determine this potential by examining the RLC properties (aswell as noise rejection capabilities and contact metallurgy) to completely determine the ability, or lack thereof, for two cables to "sound different". And he later elluded that the RLC properties of a cable would have to be staggeringly out-of-the-ordinary to have any audible affect. So it's possible; Yes. But very highly unlikely to be from anything related to RLC.

Yes, that's what I thought. However, something doesn't make sense. And that something is the blind tests, and there have been many blind tests that have been done, that shows that people really CAN detect differences in cables, usually interconnects.

Usually it consists of people having to distinguish between what cable is the cheap Rat Shack and which is the $4000 wonder cables (snake oil?). Strangely, most of the time people say that the Rat Shack cable is the $4000 one, and the exotic wonder cable is the cheap one, so you get a negative result, but one that is still significant because it says that a difference has been detected. I can provide links if you guys are interested. What it tells me is that (A) expensive cables are indeed snake oil, if people prefer the cheaper one over it, and (B) others do seem to be able to tell the difference, and certain individuals can do it consistantly. There have been both formal and informal blind tests that all reach this similar result, and like I said, I can provide some links.

I would also like to see for myself, so I will be constructing my own low inductance, high capacitance interconnect and compare it to a cheap Rat Shack interconnect, to see if small differences in RLC really can impact sound. The math says it shouldn't, but something tells me I might hear a difference. I'll do a blind test with a friend and see.

[Hillbilly SQ]

maybe the people that prefer the ratshack cable are just used to how your everyday cable sounds. or maybe the expensive cable has so much technology in it that it's actually HINDERING the task the cable is supposed to be doing. notice i'm staying neutral here. i personally have a 6' ratshack cable going from my tv to my reciever. sounds fine and i don't watch near enough tv or movies to justify blowing money on snakeoil. also listen to 99.999% of music in my truck with the 3 knukonceptz karma cables going from the alpine headunit sending actively crossed signals to the single jbl 6-channel that's about to get replaced by a pair of memphis amps. i've had those cheap knu cables since the summer of 04 and they're doing great. no reason to change them until i go optical with an h701 processor in the next couple years.

in the home environment slight difference MIGHT be audible in a blind test. in the car audio environment i defy anyone to hear a difference between a standard twisted pair and snakeoil cables. then again, i'm just a redneck with roaring a/t's for tires and a magnaflow exhaust dumped near the spare tire. :p

[MarkZ]

Yes, that's what I thought. However, something doesn't make sense. And that something is the blind tests, and there have been many blind tests that have been done, that shows that people really CAN detect differences in cables, usually interconnects.

I'd have to see the methodology of the specific tests in question. But keep in mind that making the test double blind isn't the only control that needs to be performed.

Personally, I think that if you can accept that it's only the RLC parameters of the cable that are important, then you can modulate those three parameters in a test to derive psychometric curves. In other words, if you can increase inductance (with a series inductor) to the point where you can pinpoint the amount of inductance it takes for your subjects to notice a statistically significant difference, then you have something more to go on. Likewise for capacitance and resistance. Otherwise, you always have the issue of subject bias -- people could always make the claim that they just didn't WANT to hear any differences, so that's what they reported. But if you have psychometric curves to look at, it eliminates that possibility (kinda sorta) and gives you a measure of individual subject variability.

Psychophysics is a very complex and underappreciated field. It's not something that's as simple to control for as some people may think. Pick up the SS Stevens book on psychophysics and you'll see what I mean. Fortunately, the one I'm thinking of is short (and relatively cheap!).

[werewolf]

not much time tonight , but you guys have pretty much nailed it. Here's the important points, briefly, off the top of my head:

1. Yes, it is possible for cables to sound different.
2. If they are found to indeed sound different ... in controlled tests where the only possible variable is the cable (and please never forget my opening statement about scraping oxidation in a same-cable test, for example) ... there's no theory or evidence to suggest anything other than RLC parameters (noise shileding, contact metallurgy aside). Linear system theory is well understood guys ... no mystery surrounding electrical transport of a 20kHz signal over a few feet of wire. And by far, wire is the most linear element in the electronic capture and reproduction of music.
3. Some interconnects may contain mysterious little "network boxes" that manipulate ... guess what? ... and will demonstrate measurably different frequency responses (magnitude and phase) as a result ... demonstrating the simple fact that equalizers can manipulate the "sound" :)
4. We have not yet done a speaker cable example ... but we will, probably focusing on a rather inductive cable loaded with a rather capacitive speaker (like an electrostat).

i think i've said it before ... but one of these statements is very boring, while the other is (potentially) very interesting :

1. "Me and some friends tested some cables, and they sounded different!"
2. "A cable test was performed in a well-controlled, double-blind environment where all other variables were compehended, and a sonic difference in cables ... beyond that explainable by random guessing ... was registered. Furthermore, the frequency responses ... including magnitude and phase versus frequency ... of the cables were measured in-place, and RLC analysis (also noise shielding and contact metallurgy, of course) was found to be inadequate to explain the difference."

If there's any links supporting statement number 2 ... all of statement number 2 ... i'd be happy to read them :) No compelling reason to discard a few centuries of well-developed logic, network and electrical theory UNLESS & UNTIL those theories are conclusively demonstrated to be inadequate.

[chad]

i think i've said it before ... but one of these statements is very boring, while the other is (potentially) very interesting :

1. "Me and some friends tested some cables, and they sounded different!"



You forgot to add... "It took my friend and I each a 6 pack to install or decide the second cable sounded different, it certainly had less high end" :p

[avaxis]

If there's any links supporting statement number 2 ... all of statement number 2 ... i'd be happy to read them :) No compelling reason to discard a few centuries of well-developed logic, network and electrical theory UNLESS & UNTIL those theories are conclusively demonstrated to be inadequate.

does these comparisons count?
http://www.audioholics.com/techtips/audioprinciples/interconnects/SpeakerCableFaceoff.htm
http://www.audioholics.com/techtips/audioprinciples/interconnects/speakercable2p1.php

for me, i just want to know what is the cheapest speaker/interconnect cable with the most suitable RLC figures and sufficient shielding to be used in a car environment. i'd appreciate if anybody has the answer cause majority of the maths in this thread isn't doing my brain any good.

[fej]

I still like this thread.

My only question is this:

IMO there are two BASIC (with MANY variations) kinds of people when it comes to audio, those that turn the treble knob up, and those that turn the bass knob up ... explain that ;)

[werewolf]

does these comparisons count?
http://www.audioholics.com/techtips/audioprinciples/interconnects/SpeakerCableFaceoff.htm
http://www.audioholics.com/techtips/audioprinciples/interconnects/speakercable2p1.php

absolutely NOT !!! :p

Those links provide a very thorough analysis of RLC parameters, and the corresponding frequency responses, of various loudspeaker cables. They are very good links, by the way :)

These links lay a solid foundation for showing how RLC analysis explains any sonic "attributes" of speaker cables, pretty much the exact opposite ... or antithesis ... of what i was asking for :p

I was asking for conclusive evidence that RLC analysis is inadequate to explain any (demonstrably real) sonic difference in cables ... anyone?

[fuscobal]

Now, that the RLC impact has been discussed enough ( i think ?!?!), what about talking about noise shileding and contact metallurgy. What makes a "good" contact and how should a propper shielding look like in a car cable ? Real good and bad cable examples would be even better !

[Whiterabbit]

contact is interesting. Do we have any concrete data showing contact resistance values? I'd be willing to bet qualitatively we arent gonna see much change between ETP copper and high purity gold/silver.

But what contact metallurgy should bring to mind are features "unrelated" to the "science" of cables as they relate to sound. Namely, lifetime, fatigue, and whether the science of the cable will be the same after five years of vibration and thermal cycling :) Could that be affectec by contact metallurgy? possible, but likely processing will play a larger role than material.

[SSSnake]

Shielding is definitely an area that needs debunking (twisted pair no shield vs no twist overall shield). For single ended transmission, I vote no twist overall shield but I am willing to be educated.

BTW IMO - Locking RCAs are worth the price in a car!!!