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The source of this "myth" is the commonly held belief that oval speakers are incapable of producing the high fidelity sound that a round speaker is capable of. Note that I'm not in any way stating that an oval speaker is in fact superior, but simply that in many if not most cases an oval speaker can equal and in some cases better it's equivalent round speaker.

The common argument is that the larger and/or odd shape of the cone causes flex in the cone itself and creates more distortion due to a round shape being inherently more stiff. Also, the fact that oval speakers create an odd dispersion pattern as they approach beaming, which they do, but it's not necessarily a detriment.

The problem with this is that it is somehow thought that the common round speaker is inherently very stiff which really isn't the case. It is also believed that an oddly shaped speaker somehow needs huge amounts of reinforcement to approach any level of cone stiffness, which is also untrue. Most "cone flex" is due to the design of the cone itself. If you take a look at the typical speaker, the majority of them use polypropylene or paper cones, which most of them you can easily "bend" or flex simply by pressing on the edge of the cone near the surround. In fact, the only cone designs out there that really achieve a level of stiffness close to achieving the goal of true pistonic behavior would be extreme composites like Kevlar and some metal cones that have a LOT of material density such as the SEAS magnesium cones or the one case of their L18 7" driver which uses a specifically designed cone profile to achieve more stiffness and push the breakup node to a much higher frequency. The other issue presented is the material density required to get such a stiff cone usually results in a heavy cone in and of itself meaning a hit in sensitivity of the speaker.

What sounds worse: a broad, large increase in even order harmonic distortion in the lower midrange and bass or sharper but narrow band odd order harmonic distortion in the upper treble? This is the classic damped cone vs stiffer cone debate. A very stiff cone generally has lower distortion in the passband but much higher as it approaches the treble region (right before the point that you'd usually hand off to a tweeter) It also means that you are going to have a breakup node somewhere. In extremely stiff drivers like a W18 or W22EX SEAS magnesium cone, this is very apparent to the point that a notch filter has to be designed and the crossover has to be low enough so that harmonic distortion doesn't excite this breakup node. Though not to the same extent, breakup nodes still occur even in the case of softer poly and paper cones. If the design is soft (damped) enough, there's less and less chance of a big nasty breakup node, but more chance of having more distortion overall in the passband due to less than pistonic behavior. But round vs oval cones in this area? Referring to distortion/resonances generated by the cone itself, round cones tend to have a single breakup peak due to being symmetrical. Oval cones, due to their odd/dissimilar cone profile and their not being symmetrical all around tend to lessen single distortion peaks and "spread it around". A lot of the time, they can have less overall distortion in the region where "breakup" would occur due to this.

The other argument is dispersion pattern. A round cone, being symmetrical, disperses more "evenly" than an oddly shaped cone does. People claim that an oddly shaped cone, say a 6x9 for example, "beams like a 9" driver" which is not entirely true. Take a ribbon tweeter for example, which is much taller than it is wide. The narrower horizontal axis tend to have much better dispersion than the taller vertical axis. So the horizontal off axis performance is very good, where the vertical axis has "poor" dispersion comparatively. Is this necessarily a bad thing? Depends on the application. Of course, the frequencies affected are the ones that the wavelengths are smaller than the cone area, essentially frequencies "confined" within the dimensions of the speaker itself. The 6x9, for example, will beam like a 6" driver on the 6" axis, and like a 9" driver on the 9" axis. You could potentially use this to your advantage, especially in the car or a highly reflective environment where you want a higher direct to indirect sound ratio. A driver that beams like a 9" on a given axis means surfaces in line with said axis are not reflecting as much content as the speaker approaches the treble region, where the 6" axis can be aimed more toward the listener. This is not dissimilar to a line array, where multiple drivers are lined on a given axis, usually vertical to minimize floor and ceiling reflections. Of course, a line array causes the drivers to have cancellation on a certain axis across the full bandwidth of the drivers in question.

The last point: the intended application of an oddly shaped speaker is to offer more cone area where a round speaker otherwise would not fit. Not many people are considering 6x9s in place of an 8", which both of them are pretty close to one another in terms of surface area of the cone. Most people are entertaining putting something like a 6x9 in a place where the only other option is a 6 or 6.5" driver and perhaps a tweeter. A 6x9 has very close to double the cone area of a 6" driver. This can be effective in a lot of different ways. Such a driver can be designed to accomplish a much lower bass response (around an octave). Such a driver can be around 3db more sensitive on the same power level across the same bandwidth. Cone area wins over excursion for performance every time. There is a reason that pro audio opts for gigantic midbass and midrange drivers. You can accomplish much higher output levels and much lower distortion levels. To do the same with smaller drivers, you would have to have huge excursion (which despite how exotic the motor, you will always increase distortion as the required excursion level increases and the coil is forced to move further away from center position and the BL decreases). You would run into issues with power compression. You'd have to have monster amplifiers to drive them.

This all said, it is not indicative of the current offerings of the market as generally speaking, there are not many examples of "high end" oddly shaped drivers for car audio. But it is not due to an inherent disadvantage of the design itself, just due to a lack of good examples to base off of.
 

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Should be filed away in a diyma cabinet of well reasoned arguments... im confused on the breakup nodes though

seas l18 7"

https://www.madisound.com/store/product_info.php?products_id=818

breakup node at 6khz

if there were a seas l18 6x9 would the breakup node be a bunch of smaller peaks starting before 6khz, or what might it look like
 

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interesting point of view... do u think there is significant difference between square shape subwoofer compared with same brand and power one with usual shape?!
 

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...The other argument is dispersion pattern. A round cone, being symmetrical, disperses more "evenly" than an oddly shaped cone does. People claim that an oddly shaped cone, say a 6x9 for example, "beams like a 9" driver" which is not entirely true. Take a ribbon tweeter for example, which is much taller than it is wide. The narrower horizontal axis tend to have much better dispersion than the taller vertical axis. So the horizontal off axis performance is very good, where the vertical axis has "poor" dispersion comparatively. Is this necessarily a bad thing? Depends on the application. Of course, the frequencies affected are the ones that the wavelengths are smaller than the cone area, essentially frequencies "confined" within the dimensions of the speaker itself. The 6x9, for example, will beam like a 6" driver on the 6" axis, and like a 9" driver on the 9" axis. You could potentially use this to your advantage, especially in the car or a highly reflective environment where you want a higher direct to indirect sound ratio. A driver that beams like a 9" on a given axis means surfaces in line with said axis are not reflecting as much content as the speaker approaches the treble region, where the 6" axis can be aimed more toward the listener. This is not dissimilar to a line array, where multiple drivers are lined on a given axis, usually vertical to minimize floor and ceiling reflections. Of course, a line array causes the drivers to have cancellation on a certain axis across the full bandwidth of the drivers in question...
I will not comment on the other points because I'm sure more knowledgeable members can chime in on the subject.

Regarding what I left from your post, Eric Stevens told me once the exact opposite of what you said.
It's true that a 6x9 will beam like a 9" (longest side) but will also beam like a 6" (shorter side). Good analogy with the ribbon drivers ;)
Putting a 6x9 (longest side parallele to the ground) in the kicks in a sport car will beam like a 6" driver.
Putting a 6x9 (longest side parallele to the ground) in the kicks in a truck will most likely beam like a 9" driver.

It's all about orientation. If you install it in the door, try to aim the shorter side to your left ear so that beaming can occur higher in freq.

Another advantage to using oval drivers (and you've said it) is for increased surface area where round drivers of the same cone area wouldn't fit.

You can call it good marketing from ID if you wish, but I agree with what Eric (ex ID) told me.

Kelvin
 

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I have recently been trying to get this through some peoples heads, 6x9's are not the enemi to SQ and actually have more beneftis then cons IMO especially in a car.

Great write up.
 

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Cone area wins over excursion every time.
Great post.

It never ceases to amaze me how often that statement demonstrates itself to be fundamentally true.

I'm not saying there is not a time and place for high excursion, quite the opposite actually, but it is a compromise born out of necessity.

Speaking of compromise, non-round speakers certainly have their advantages, and like nearly anything else they can perform just as well if they are implemented properly.
 

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Typically the problem I have run into is that the oval speakers will typically distort at higher power faster than the equivilent round version. So it mainly depends on the aplication of the speaker. I see a 6x9 in a different category than a 4x6 or 4x10 anyway, can't really get a whole lot out of those anyway.
 

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Typically the problem I have run into is that the oval speakers will typically distort at higher power faster than the equivilent round version. So it mainly depends on the aplication of the speaker. I see a 6x9 in a different category than a 4x6 or 4x10 anyway, can't really get a whole lot out of those anyway.
^ that's really a design issue.
Most older 6x9 were coaxial that were designed with either a small amp to power them or even the HU.

My ID XS69 doesn't distort with 300rms HP set @ 100Hz 24dB/oct slope.

Kelvin
 

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I am not convinced....

Dont get me wrong a 6X9 can get a person increased cone area on a rear deck shelf allowing more output with a weak OEM deck but lets talk about the intent of the driver....is it a sub? is it a mid?...wtf is it?

I have never heard a 6X9 have the bass output of a quality 8" sub (arguably the 6X9 would have close to the cone area of an 8"), and I have never heard a 6X9 sound like a good quality 6.5 mid.....so where does that leave the 6X9?

ALSO....

So the 6X9 typically is designed for a little more bass output....so how does that work with a true dedicated sub?;...so we tweak the XO to the point the sub is sloped below the 6X9s capabilities or maybe we just have 2 different drivers sizes playing in the same zone?

AND....

New square drivers designed to play in a limited spectrum undergo full FEA stress analysis and are designed that stress loads over the cone surface are supported and reinforced in order to prevent the cone from breaking (note the star shaped bracing on the face of the Kicker square drivers). The uneven stress loads on the cone was a HUGE problem for subwoofer designers to overcome and by proxy of the even loads distributed and relatively easy(er) to engineer on round cones is exactly why square drivers did not come out sooner. This tecknology was not around when egg shaped drivers were originally being designed.

The egg shaped driver to have any real low Hz output would ideally need to have more structural integrity on the 9" spans then the 6" side....now the heavier cone mass looses the ability to effectively play upper hz...making it bad as a sub and worse as a mid.



IMO, if you are looking to put a driver in the rear deck of your 91 Camaro, with no sub and some sweet paper cone coaxials up front, a 6X9 is the perfect choice....that is as long as you have an EQ-booster under your dash to tweak the sound just right.

~JH
 

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I am not convinced....

Dont get me wrong a 6X9 can get a person increased cone area on a rear deck shelf allowing more output with a weak OEM deck but lets talk about the intent of the driver....is it a sub? is it a mid?...wtf is it?

I have never heard a 6X9 have the bass output of a quality 8" sub (arguably the 6X9 would have close to the cone area of an 8"), and I have never heard a 6X9 sound like a good quality 6.5 mid.....so where does that leave the 6X9?

ALSO....

So the 6X9 typically is designed for a little more bass output....so how does that work with a true dedicated sub?;...so we tweak the XO to the point the sub is sloped below the 6X9s capabilities or maybe we just have 2 different drivers sizes playing in the same zone?

AND....

New square drivers designed to play in a limited spectrum undergo full FEA stress analysis and are designed that stress loads over the cone surface are supported and reinforced in order to prevent the cone from breaking (note the star shaped bracing on the face of the Kicker square drivers). The uneven stress loads on the cone was a HUGE problem for subwoofer designers to overcome and by proxy of the even loads distributed and relatively easy(er) to engineer on round cones is exactly why square drivers did not come out sooner. This tecknology was not around when egg shaped drivers were originally being designed.

The egg shaped driver to have any real low Hz output would ideally need to have more structural integrity on the 9" spans then the 6" side....now the heavier cone mass looses the ability to effectively play upper hz...making it bad as a sub and worse as a mid.



IMO, if you are looking to put a driver in the rear deck of your 91 Camaro, with no sub and some sweet paper cone coaxials up front, a 6X9 is the perfect choice....that is as long as you have an EQ-booster under your dash to tweak the sound just right.

~JH
I won't tell you 6x9 is the sh!t coz I won't be able to convince you.

Try to find someone that has those: image dynamics | eBay

^ Those are not subs, they are mids. Efficient @ 93dB 1w/1m (not the 2.83v rating that most use). And can play as high as 5kHz (beaming like a 6").
Really... Find someone who has those and take a listen. I don't know what you use but the mid's clarity is outstanding. I'm just gonna let the drivers talk.

It's not because you've never heard a good 6x9 that it doesn't exist.

Kelvin
 

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ovals aren't inherently better or worse than round speakers and the ultimate performance does depend on the rest of the design.

However, the oval shape does "spread the chaos" of bending modes around, which often results in a diminishing of the peaks and dips caused by those modes. The different dispersion patters along long and short axes can also be helpful, but a 6x9 woofer (just like other speakers) ought to be low passed before the dispersion narrows if you're using it in a car.
 

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Excellent thread!

Regarding what I left from your post, Eric Stevens told me once the exact opposite of what you said.
It's true that a 6x9 will beam like a 9" (longest side) but will also beam like a 6" (shorter side). Good analogy with the ribbon drivers ;)
Putting a 6x9 (longest side parallele to the ground) in the kicks in a sport car will beam like a 6" driver.
Putting a 6x9 (longest side parallele to the ground) in the kicks in a truck will most likely beam like a 9" driver.

It's all about orientation. If you install it in the door, try to aim the shorter side to your left ear so that beaming can occur higher in freq.

Another advantage to using oval drivers (and you've said it) is for increased surface area where round drivers of the same cone area wouldn't fit.

You can call it good marketing from ID if you wish, but I agree with what Eric (ex ID) told me.

Kelvin
- This is true! Google "Oblique" cones also... I have personally tested this with an oblique cone and it's true.

Also, an oval cone has lower midrange distortion, everything else being equal.

But for extreme SPL subwoofers, physics may dictate that a round cone would have a better stiffness to weight ratio? Not really sure on that one.

But for midbass/midrange drivers and sound quality systems, they can work great... to this day, one of the best mids I've ever heard was a 6X9... it had very wide bandwidth, low distortion, and efficiency. If I were going into competition, I'd consider that Image Dynamics XS 6X9 comp set.
 

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I have tried Image Dynamics XS69 from Mr. Eric Stevens.
This mid 6"x9" has an excellent mid-clarity.

I am agree with Mr. Kelvin.

And Myth: Oval/"odd" shaped speakers can't sound as good as round speakers >>> of course not true, if you use XS69 Image Dynamic.
 

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ovals aren't inherently better or worse than round speakers and the ultimate performance does depend on the rest of the design.

However, the oval shape does "spread the chaos" of bending modes around, which often results in a diminishing of the peaks and dips caused by those modes. The different dispersion patters along long and short axes can also be helpful, but a 6x9 woofer (just like other speakers) ought to be low passed before the dispersion narrows if you're using it in a car.
So are you saying don't cross too low or it will beam?
 

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I installed the first set of 6x9's I ever saw 43 years ago, I believe Sparcomatic or something similar, Motorola 8 track, 58 Bonneville. Then my country bumpkin brother and I went to the City, Spokane, and cruised the main drag, the only system there, we were pioneers in audio cruising in Spokane it seems:)

Only a few oval speakers have ever been worth a crap and when done right, superb. I recently removed my ID X69 and horns from my Duramax as getting ready to sell it, I absolutely loved the results of that setup, if I was using the same level of HU and processors as I used on my Rainbow Ref system I might of liked it the best out of everything I have ever done. (except center imaging which just does not work really well in a full size truck no matter what you do)

I have been on the cannot stand side of the 6x9 argument most of my life, still am for 99.99% of the craps that is sold. I love the X69, one of my favorite speakers yet:)

Rick
 

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I wish I could find it...

Long ago, I saw a little high-speed video clip of a 6x9...

the cone was flapping like wings of a seagull...

Now, obviously, different companies will design better cones to reduce this.. but the fact is, in it's application, an oval cone simple isn't as stiff, in a reactive sense of that of a simple round cone...

how much of this actually relates to sound quality could only be determined though extensive testing...

Sure a CF cone 6x9 is going to sound good, very little flex... but how about a simple poly cone... ?
 
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