141 - 160 of 174 Posts

#### Holmz

·
Joined
·
3,358 Posts
This link also has some useful info for the OP, and Oscar.
Thiele / Small parameters explained with real world cases
Motor force...
However Oscar's addition of the current is talking about "the force that the motor exerts"... and hence resistence does come into play.
(So I am not there is anything to suck?)

Basically the motor does not produce any sound when the I is zero.
And I assume that damping factor again comes into play as a possible theory for the OP?

#### ckirocz28

·
##### Registered
Joined
·
1,295 Posts
(So I am not there is anything to suck?)
Haha.
Oscar's addition of current has no bearing on the argument, it changes the motor force argument to a sensitivity argument.

#### Holmz

·
Joined
·
3,358 Posts
Haha.
Oscar's addition of current has no bearing on the argument, it changes the motor force argument to a sensitivity argument.
I don't believe he needs to be insulted, but if I did choose that path, then I would have at least referenced Myer to be more complete.
(But as I see nothing wrong in his post, therefore I wouldn't.)

It appears like Oscar's post is relevant in terms of damping factor as that is a current dependent right off the bat. The whole argument about "more whack" is about resistence (2 vs 8 ohms) and therefore a lot about current.

#### ckirocz28

·
##### Registered
Joined
·
1,295 Posts
I don't believe he needs to be insulted, but if I did choose that path, then I would have at least referenced Myer to be more complete.

(But as I see nothing wrong in his post, therefore I wouldn't.)

It appears like Oscar's post is relevant in terms of damping factor as that is a current dependent right off the bat. The whole argument about "more whack" is about resistence (2 vs 8 ohms) and therefore a lot about current.
We were talking about motor force (not damping factor), as was the OP. Motor force is a speaker characteristic that doesn't change, damping factor is an amplifier characteristic that does.
As for the insult, Oscar came at me the same way in another thread, apparently trying to prove he's the smartest guy in the room, hence my question about his IQ.
Regarding "yelling" at the OP about motor force, he doesn't yet understand it, no one explained it, he kept arguing, so I yelled. Enter Oscar without a good grasp on the subject I was "yelling" about.

#### Holmz

·
Joined
·
3,358 Posts
We were talking about motor force (not damping factor), as was the OP. Motor force is a speaker characteristic that doesn't change, damping factor is an amplifier characteristic that does.
As for the insult, Oscar came at me the same way in another thread, apparently trying to prove he's the smartest guy in the room, hence my question about his IQ.
Regarding "yelling" at the OP about motor force, he doesn't yet understand it, no one explained it, he kept arguing, so I yelled. Enter Oscar without a good grasp on the subject I was "yelling" about.
Ok then I have a question:

In post #69 there is a T/S image.
The BL in series is listed a series 10.9 and in parallel it says 22.48.

...
Your math on BL is totally wrong too, Mr. World's Smartest Man. It's opposite of how it really works. You said that you have 4x the motor force wired at 2 Ohms compared to 8 Ohms. lol no you don't. This W12K9D4 subwoofer makes over twice the motor force wired at 8 Ohms than 2 Ohms. I'm attaching a pic of the TS Parameters of this subwoofer. Look at the BL and look at the resistance in Ohms, listed as "Re". You can quit barfing out the wrong information now, thank you. Notice how it doesn't show 4x the motor force in 2 Ohms compared to 8 Ohms. In fact it shows 1/2x the motor force at 2 Ohms compared to 8 Ohms.

Explain that with your fancy audio math, Mr. Always Correct.

...
How come it is not 10.9 and 21.8?
Why is the parallel BL not exactly twice of the series BL number?

#### ckirocz28

·
##### Registered
Joined
·
1,295 Posts
Ok then I have a question:

In post #69 there is a T/S image.

The BL in series is listed a series 10.9 and in parallel it says 22.48.

How come it is not 10.9 and 21.8?

Why is the parallel BL not exactly twice of the series BL number?
I don't know, the length of wire in the gap remains the same, the magnetic flux remains the same, you got me. That's why Bl/Re is a more understandable way to look at it.
If you look at the other specs that understandably change, Le and Re as examples, they all change in the same ratio. A dual 2 ohm voice coil sub makes easy math:
Wired parallel Re = 1 ohm
Wired series Re = 4 ohms
Parallel Le = 1 mH
Series Le = 4 mH
Parallel wiring results in some specs changing by a 4 to 1 ratio, others change in a 1 to 4 ratio. Why is Bl the one spec that shouldn't change yet does, but not in the same ratio (Bl changes in a 2 to 1 ratio)? I think the method of measurement or formula is wrong, because it doesn't jive with the definition of the measurement being defined by physical qualities that don't change. I know all of the modeling programs report the same change, but the definition describes a spec that can't change, it's purely determined by physical characteristics that don't change. I include magnetic flux as physical because it is determined by the magnet and gap, both physical items.

#### ckirocz28

·
##### Registered
Joined
·
1,295 Posts
Also, all of the speaker manufacturers report the same change in Bl with different wiring methods, yet all of the modeling programs report identical results with identical watts applied, with the exception of a very slight change in frequency response due to the change in inductance (Le). What's going on? I don't know. I just know the definition of motor force (Bl) is based on physical attributes that don't change no matter how you wire the amp or how much power is applied.

#### ckirocz28

·
##### Registered
Joined
·
1,295 Posts
Also, all of the speaker manufacturers report the same change in Bl with different wiring methods, yet all of the modeling programs report identical results with identical watts applied, with the exception of a very slight change in frequency response due to the change in inductance (Le). What's going on? I don't know. I just know the definition of motor force (Bl) is based on physical attributes that don't change no matter how you wire the amp or how much power is applied.
Now that I've thought about it, I'm probably wrong about the change in inductance.

#### Holmz

·
Joined
·
3,358 Posts
Also, all of the speaker manufacturers report the same change in Bl with different wiring methods, yet all of the modeling programs report identical results with identical watts applied, with the exception of a very slight change in frequency response due to the change in inductance (Le). What's going on? I don't know. I just know the definition of motor force (Bl) is based on physical attributes that don't change no matter how you wire the amp or how much power is applied.
Bl does not seem to have inductance in it, nor is a frequency defined.
So I am not sure how it changes the motor force.

But the manufacturers seems to have different numbers for motor force between parallel and series.

If the inductance changes, then perhaps that could be a mechanism for the OP's assertion if what he hears being different?

#### Jonathan2

·
##### Registered
Joined
·
10 Posts
I don't know, the length of wire in the gap remains the same, the magnetic flux remains the same, you got me. That's why Bl/Re is a more understandable way to look at it.
If you look at the other specs that understandably change, Le and Re as examples, they all change in the same ratio. A dual 2 ohm voice coil sub makes easy math:
Wired parallel Re = 1 ohm
Wired series Re = 4 ohms
Parallel Le = 1 mH
Series Le = 4 mH
Parallel wiring results in some specs changing by a 4 to 1 ratio, others change in a 1 to 4 ratio. Why is Bl the one spec that shouldn't change yet does, but not in the same ratio (Bl changes in a 2 to 1 ratio)? I think the method of measurement or formula is wrong, because it doesn't jive with the definition of the measurement being defined by physical qualities that don't change. I know all of the modeling programs report the same change, but the definition describes a spec that can't change, it's purely determined by physical characteristics that don't change. I include magnetic flux as physical because it is determined by the magnet and gap, both physical items.
You have probably already figured thsi out, but here are my 2 cents.
Your assumption that the length of wire in the gap remains the same in parallell or series connection is false. In series the wire length doubles compared to having only one coil connected. But in parallel it doesnt. The wires are parallel, so they act like one thick wire. It can also be called bifilar winding. In parallel the two coils are seen as one coil. As long as they are shorted together in both ends it doesnt matter how many wires in parallel, they are seen as one single wire.

#### Jonathan2

·
##### Registered
Joined
·
10 Posts
Ok then I have a question:

In post #69 there is a T/S image.
The BL in series is listed a series 10.9 and in parallel it says 22.48.

How come it is not 10.9 and 21.8?
Why is the parallel BL not exactly twice of the series BL number?
The coils are not exactly the same. You are winding wires on top of each other. I havent analyzed voice coil windings, only transformer/inductor windings. They are very similar though. First layer is usually easy to get very tight. The other layers are not as tight, so they are not the exactly same. And the length of a turn is not the same on each layer since the diameter of the winding changes.
Bl is flux x length of wire, not turns.

Also, the measuring equipment is not 100% accurate.

#### Holmz

·
Joined
·
3,358 Posts
The coils are not exactly the same. You are winding wires on top of each other. I havent analyzed voice coil windings, only transformer/inductor windings. They are very similar though. First layer is usually easy to get very tight. The other layers are not as tight, so they are not the exactly same. And the length of a turn is not the same on each layer since the diameter of the winding changes.
Bl is flux x length of wire, not turns.

Also, the measuring equipment is not 100% accurate.
The actual equation is flux * area * number windings... so area * N is effectively proportional to length.

If they measure these things, then it would seem like the number should be double... or there is some nuance that we don't appreciate.

#### ckirocz28

·
##### Registered
Joined
·
1,295 Posts
You have probably already figured thsi out, but here are my 2 cents.

Your assumption that the length of wire in the gap remains the same in parallell or series connection is false. In series the wire length doubles compared to having only one coil connected. But in parallel it doesnt. The wires are parallel, so they act like one thick wire. It can also be called bifilar winding. In parallel the two coils are seen as one coil. As long as they are shorted together in both ends it doesnt matter how many wires in parallel, they are seen as one single wire.
Got it.
But I feel like Bl/Re should be the reported measurement for motor strength since it isn't affected by series or parallel wiring choices.
http://www.woofertester.com/dvcdrivers.htm

·
Joined
·
1,295 Posts

#### Rockworthy

·
##### Registered
Joined
·
42 Posts
Discussion Starter
Funny thing, since that setup didn't impress me, I switched to the Infinity Perfect 10.1 subs (just two) and an Infinity 611a to power them. It had a clip light, do I used that to set the gain. Night and day difference in clarity and impact from the old setup, but I also had the gain much closer to correctly set with the new setup, which makes it by no means a fair comparison in hind sight.

I picked up the 3rd perfect 10.1 later when I switched cars and wanted to move down to just one sub. I couldn't justify pulling one of the two and using it, then if I wanted to l run two later, one would have been played so much more than the other and I felt it would have changed how the two behave. Never ran all (3) together, just have (3).
Ok I just checked in on this thread again because I have some exciting progress on this whole "I want more impact from my subwoofer" thread. Exciting progress I can't wait to tell you all about....

...But first, I want to give props to this Weigel21 gentleman, who does my heart good with his talk about his three Infinity Kappa Perfect 10.1 subwoofers. Yes! This guy knows what's up with clarity and impact. As a matter of fact, since the last time I posted on this thread, after searching eBay almost every day for an old Infinity Perfect sub, I actually found one and bought it! I was hoping to find a 12.1 just like my old one, but I could only find a 10.1 so I bought that one! I put it in the recommended .6 ft^2 sealed enclosure, and popped it into my truck, and WHAMMO! Finally there was that impact that I was looking for all along! Just like I remembered my 12.1 to be. It's musical, it's accurate, you feel every bass strike deep in your solar plexus, just amazing. Just what I remembered. So much better than both the stupid new Infinity K1200 and the Rockville K9 12".

Another sensation you get with these Infinity 10.1 drivers is you feel the texture of all the other bass notes too, not just the super low ones. For instance bass guitar, things that are just kinda mid-bassy not sub-bassy, you can feel the seat you're in vibrating, the hair on your arms and your clothes vibrating, etc. I don't know what the hell kind of magic Infinity built these things with, but it's so impressive that all subwoofers should be designed like this as a basic setup, and tweaked from there.

I really wish I had a pair of X-ray goggles so that I could look into the subwoofer's voice coil area and see how it's made inside so that I can try to understand why this thing creates that dynamic, accurate, tactile type of bass instead off a loose, muddy, boring disaster that is the average subwoofer. Question to Weigel21: what the hell is going on inside there? Why is it so much more fun to listen to? What drew you to these Perfect 10.1 drivers too? For myself, I bought the 12.1 after I read an article in an audio magazine that did an in-depth review.

Before I switched out the Rockville W12K9D4 for the Infinity 10.1, I also bought a really powerful amp just to make sure I was giving that K9 all the power it needed. It does 3000 watts RMS at 2 Ohms. It's called a Taramps HD3000. Didn't change the sound quality one bit, as far as I could tell. Oh it gets unbelievably loud, but the sound and tactile characteristics didn't change. Oh well, at least I have enough extra power on tap now to tear a hole in the universe.

Oh, one more little surprise for my fellow subwoofer nerds: I bought a used Acoustic Elegance SBP15 subwoofer off of eBay too, that just arrive this morning. I don't have an enclosure for it yet, I'm going to have to build one so it will be a while before I can report on how awesome it sounds, but according to my research online, this subwoofer is designed to be, basically, the most accurate, crunchy, detailed, SQ type of subwoofer ever to be created by mankind. I'm sure a lot of you guys out there already know about Acoustic Elegance subwoofers. I'll report back later on how that thing sounds compared to the Infinity Perfect 10.1. Could it be even more accurate and tight than the 10.1? Hard to say but we'll find out.

#### gijoe

·
##### Registered
Joined
·
7,350 Posts
Oh, one more little surprise for my fellow subwoofer nerds: I bought a used Acoustic Elegance SBP15 subwoofer off of eBay too, that just arrive this morning. I don't have an enclosure for it yet, I'm going to have to build one so it will be a while before I can report on how awesome it sounds, but according to my research online, this subwoofer is designed to be, basically, the most accurate, crunchy, detailed, SQ type of subwoofer ever to be created by mankind. I'm sure a lot of you guys out there already know about Acoustic Elegance subwoofers. I'll report back later on how that thing sounds compared to the Infinity Perfect 10.1. Could it be even more accurate and tight than the 10.1? Hard to say but we'll find out.
I'm glad you found the sound that you were after. I'd almost guarantee that the SBP is going to be much lower distortion, and have much lower inductance, so it will play higher (although in a car it will probably be low passed before that's even relevant). Because of the (suspected) lower distortion it won't sound as loud as the 10.1 at a given SPL, but the SBP15 will use less excursion to reach that SPL, lowering distortion even more, and giving it the potential for quite a bit more SPL than the 10.1. I'm betting that the 10.1 is going a good sub compared to the SBP, but nothing exceptional, maybe like a good ol' IDQ10. I'm interested in hearing about the results, especially if you're able to give some objective information on the differences.

#### Rockworthy

·
##### Registered
Joined
·
42 Posts
Discussion Starter
I'm glad you found the sound that you were after. I'd almost guarantee that the SBP is going to be much lower distortion, and have much lower inductance, so it will play higher (although in a car it will probably be low passed before that's even relevant). Because of the (suspected) lower distortion it won't sound as loud as the 10.1 at a given SPL, but the SBP15 will use less excursion to reach that SPL, lowering distortion even more, and giving it the potential for quite a bit more SPL than the 10.1. I'm betting that the 10.1 is going a good sub compared to the SBP, but nothing exceptional, maybe like a good ol' IDQ10. I'm interested in hearing about the results, especially if you're able to give some objective information on the differences.
Thanks for the encouragement. Yeah I simply can't wait to compare the 10.1 and the SBP15 and report back here on the difference. This has been a fun journey learning more about subwoofers and sound quality, and I was so lucky to find either one of these subwoofers on eBay for cheap, let alone both. The subwoofer gods are smiling upon me.

Dude yeah the IDQ10. Isn't that from Image Dynamics? I have read great things about those too, and I was searching for used Image Dynamics subwoofers on eBay too. From what I've read online those are the go-to affordable sound-quality subwoofers. People are using the same type of language to describe them as they do about the Infinity Perfects. Have you had any Image Dynamics subwoofers? What has been your impression of them?

Oh another couple quick observations on the topic of sound quality from the Infinity 10.1:

Observation #1: The published in-car frequency response peaks at 18Hz! That's incredibly low! Especially for a little 10-incher! Simply incredible. I think Infinity used several tablespoons of dried unicorn powder in the manufacture of each 10.1.

Observation #2: However, not only does this thing play super low, but man is it tight. What I've observed is that even when several different low notes are played on top of one another, it accurately plays them all at once and you can still pick out the different notes. So cool. Compared to this Infinity the Rockville K9 sounds like a bowl of mashed potatoes. Also while it's steadily playing a really low note, like the one I'm thinking about is around 25 or 30 Hz, and then there is an impulse from a drum (or something that sounds like a kick drum), you still get that "whack" in your chest from the impact of the drum. That's something the K9 was bad at too. "Transient response" is the name of the game with this thing. Just heaven.

Observation #3: There is some distortion with this little guy, not noticeable most of the time but when I do a sine sweep down to 20 Hz at very high volume there is definitely a soft "whooshing" sound that you can hear. Not noticeable during music playback, not by me anyways, but there it is. I reckon most if not all subwoofers will do this with enough volume eventually, and I further reckon there is nothing anyone can do about it, so I'm not going to worry about this at all.

#### Holmz

·
Joined
·
3,358 Posts
I'm glad you found the sound that you were after. I'd almost guarantee that the SBP is going to be much lower distortion, and have much lower inductance, so it will play higher (although in a car it will probably be low passed before that's even relevant). Because of the (suspected) lower distortion it won't sound as loud as the 10.1 at a given SPL, but the SBP15 will use less excursion to reach that SPL, lowering distortion even more, and giving it the potential for quite a bit more SPL than the 10.1. I'm betting that the 10.1 is going a good sub compared to the SBP, but nothing exceptional, maybe like a good ol' IDQ10. I'm interested in hearing about the results, especially if you're able to give some objective information on the differences.
Arguably if it does have lower distortion than I can likely be crossed over higher...
Which then allows the woofer to be HPF a bit higher, which also may lower its distortion...

None of that will make it sound louder, and some people may not like that sound, but it is interesting.

#### gijoe

·
##### Registered
Joined
·
7,350 Posts
Arguably if it does have lower distortion than I can likely be crossed over higher...
Which then allows the woofer to be HPF a bit higher, which also may lower its distortion...

None of that will make it sound louder, and some people may not like that sound, but it is interesting.
You can probably cross it higher, but you still have to be careful of localization. Even clean bass will become localizable after abou 120hz.

Rockyworthy, yes I've used IDQ's. I ran a pair in a sealed box, then the same pair IB. Later I added a third IDQ 10 IB. After that setup I ran a pair of SBP 15's IB. Now I'm running my first ported box with Audio Frog's base model sub the G10D4.

141 - 160 of 174 Posts