Acoustic Elegance AV12-X D2!

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The curves I posted are measured curves of the driver in an open test baffle. I can easily do in car measurements if you tell me which type of vehicle and enclosure you'd like measurements of. RTA isn't really sufficient though as even a 1/12th octave RTA isn't all that telling. You can have extremely deep, but narrow dips that are masked by an RTA. Unsmoothed FFT measurements are much more sufficient as they don't have this effect. This is what was done in the in-car response of Bose301's MAGV4 that I had posted.
The "silicone smeared on the cone" is a high temperature silicone good to about 500F with a very high dielectric strength. It is painted on to insulate the lead wires from ever coming in contact with the bottom of the conductive aluminum cone. We had considered using felt like most everyone else does to eliminate lead wire tap, or a silicone rubber pad attached with silicone adhesive. It turned out that the adhesive was clearly sufficient as an insulator without the silicone foam ever being attached. It also adds some further damping to the cone resonance and brings down the magnitude of the 2.4K breakup by a good 5-6dB.

Yes, in a car I wouldn't recommend over 100hz. In most cases for an SQ system where you don't need huge levels from your midbass, I'd cross over in the 50-60hz region. We do the same in most home theater setups as long as the main LCR can handle the midbass duty appropriately.

John

My super hydrolosized honeydoo mechanism can NOT refluctuate ANY tubular octogramularly emphasized magnetic coil systems!

 

[microhaxo 10+ year member]

Does anyone have any Requests for me to make a video of?

my box is 2.75 cuft at 30hz mind you.

 

[NDMstang65 10+ year member]

I think you may have a misunderstanding of how some things work. The size of the driver or mass of the cone has nothing to do with it's ability to reproduce higher frequencies. The only issue you get into with larger drivers is that as you go up in frequency you get more directional sound. Quite simply to play high in frequency and sound good you need linear inductance. Without it, the response will be different on the inner and outer strokes. This creates high amounts of distortion. High frequency response is also about efficiency. The higher the efficiency, the less power for a given SPL, the less flux modulation, the less thermal issues, the lower the distortion. This means that a larger driver can reproduce the same frequencies cleaner as it has to move less to get that SPL and is typically more efficient. Obviously there are exceptions as a larger driver can be less efficient than a smaller one in cases.

In general though, the "fastest" drivers or the ones with the quickest transient response are the ones with lowest inductance. Dan Wiggins posted this paper way back now that explained it quite well.

http://stereointegrity.com/docs/WooferSpeed.pdf

It has everything to do with size and mass at higher frequencies. If it had nothing to do with it then Why do you even have smaller tweeters? Why do you have midbasses?

Every single person would use 1 12" full range driver, in each kick panel, and it would sound phenominal, and respond within +/- 3dB from 20-20kHz. (Which is comical in and of itself to achieve this "flat" response that when you finally hear what a "flat" response is...it honestly sounds terrible to the vast majority of the population)

You are getting distortion from the cone deflecting and becoming excited (amongst other things)... ie: the 'nodes' that are in the cone that i said to put on the shaker table and analyze via the accelerometers.

It's easy to make a speaker have low inductance..that's great that you can do it. The Lambda (sorry if I spelled it wrong) is a great motor that does preform as stated. However...at the end of the day it is nothing more then copper rings inside of the motor, anybody can do that.

I can make a speaker that has 150tm of Bl...and relatively high inductance, and will still be on par with what Wiggins is talking about with respect to "Impulse Delay".

That stuff is great in a lab (Which is where the white paper was generated)..or in the middle of a field.

But when it comes down to it sit down and think about where exactly is the subwoofer typically mounted in the vast majority of cars? Do you think that ~3ms delay time you are actually going to hear? When you have a group delay of 10-12ms for the wave form to come from the back of the car..up to the front...where you are sitting in the seat...without being able to locate the woofer in the car and it blend phenomenally with the front stage being crossed higher than 100Hz?

Theory is great...when you apply it and you actually start doing things and really sit down and think about it...there is a reason why it is all still Theory..and not a Law of Science.

It's cool to look at..and it's really cool to debate about it. But when you put the food on the plate and you sit down to eat it you realize that you really can not tell the difference in your pizza being cooked at 450 degrees..and 449.9999.

You..just eat the pizza. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[ninjawhiteboy12 10+ year member]

im glad to see you had good results

 

[John_E_Janowitz 10+ year member]

So you are trying to keep mass low...but then you say the aluminum is the best material to use...but then one brings up the frequency nodes of the cone..and then you say it adds damping for cone resonances (that otherwise with paper wouldn't be there in the first place)
Wise man would have gotten teflon tubing and encapsulated the tinsel leads if conductivity was an issue...instead of gooping the cone up.

But, carry on.

In this case we have a woofer, primarily intended for use in home theater subwoofers and intended to play low in frequency. It just happens that the same driver happens to work very well as a low distortion SQ woofer as well. Efficiency is not a primary issue in a subwoofer, so there is no need to keep mass low. We could easily make them with a paper cone, take 5% off of the Mms and gain back another dB of efficiency, however it wouldn't help the low end response at all and isn't worth the effort. We have plenty of BL and efficiency is still quite high. Both the AV12X and AV12H are just under 88dB 1W. Compare that to the other driver microhaxo had.

Again, the breakup of the cone has no factor into the use for this in a subwoofer. Even if you plan to use it to 500hz, that extra bit of damping will be negligible. It's basically the fact that there are no negative effects from the silicone.

Yes, you can encapsulate the leads, however it is much more likely to wear through the tubing than through the flexible silicone over time. It also adds more stiffness to the lead wires, which although a small amount, can still put more non-linear force on the suspension that just isn't needed. Either way will work. If someone really wants the wires shielded instead, they are welcome to request it.

John

 

[ciaonzo 5,000+ posts]

I'm beginning to appreciate my apparently rare and unique occurrence as an individual who not only loves wideband, low Q, low inductance, drivers with soft suspensions, but also knows how to use them within their limits and extract all the performance they have to offer.

Some of you should be thankful John is even taking the time to humor your responses. Especially when you tell him that you haven't even read what he's had to say, let alone try to learn from it, but you'll certainly argue back with little to no experience as a designer or even a small understanding of driver parameters. Obviously this statement does not include everyone who has contributed to this thread but for those who are taking exception to what I'm saying right now, you should read and try to comprehend what John is giving you which is basically a free lesson in driver performance regarding certain things.

It's a shame that he has to come here and defend what he is obviously very good at doing because of one or two people's misuse of a product that was not intended for the abuse it suffered. I've followed all of these threads concerning AE products and John has been very forthcoming and transparent with his very thorough explanations, mostly to people who don't understand it or appreciate it, and from what my experience tells me, he has been right on every account. And I know a few things. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

It's time to show this man some respect and end the smear campaign. Every company at every point has had some type of failure, whether it was a flawed design that went out and had to be used for a given period of time to expose the flaw, or whether it was simply a fluke such as a bad part or a less than thorough QC. The important part is taking note of these problems and doing what is necessary to make things right. This might involve recalls or replacements, further R&D, and public relations, or in this case, crowd control. Point being is that John is taking on that responsibility and yet you're continuing to attempt to discredit his efforts and his products. Shameful.

 

[NDMstang65 10+ year member]

In this case we have a woofer, primarily intended for use in home theater subwoofers and intended to play low in frequency. It just happens that the same driver happens to work very well as a low distortion SQ woofer as well. Efficiency is not a primary issue in a subwoofer, so there is no need to keep mass low. We could easily make them with a paper cone, take 5% off of the Mms and gain back another dB of efficiency, however it wouldn't help the low end response at all and isn't worth the effort. We have plenty of BL and efficiency is still quite high. Both the AV12X and AV12H are just under 88dB 1W. Compare that to the other driver microhaxo had.
Again, the breakup of the cone has no factor into the use for this in a subwoofer. Even if you plan to use it to 500hz, that extra bit of damping will be negligible. It's basically the fact that there are no negative effects from the silicone.

Yes, you can encapsulate the leads, however it is much more likely to wear through the tubing than through the flexible silicone over time. It also adds more stiffness to the lead wires, which although a small amount, can still put more non-linear force on the suspension that just isn't needed. Either way will work. If someone really wants the wires shielded instead, they are welcome to request it.

John

So if it is un-needed to play over 100Hz..150Hz..500Hz....

Then why argue and push information that it can do it? Especially giving information to people who simply do not know any better and try to sway their opinion because "I said so" or based on so and so's Theory with a bunch of neat little graphs (That only a handful of people on here will understand anyhow) trying to make them believe everything is true? Because if you have graphs and theory it must be true no matter what right?

Yeah...i've got a drag boat that'l turn 14,000 rpm and do 132.56mph in the 1/4 mile...i'll sell you one even if the biggest body of water around you is a swimming pool. Because...everybody needs to know that my boat will turn 14,000 rpm and do 132.56mph in the 1/4 mile. Everybody else should have one and it should do it to...even though they'll never really use it. It sure sounds cool!

Or better yet..I bought a Indy car last week...I was going 160mph down I-10 and decided to take it off road...it didn't work out so well. But the salesman told me that this car would do anything I wanted it to do?

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[squeak9798 5,000+ posts]

So if it is un-needed to play over 100Hz..150Hz..500Hz....
Then why argue and push information that it can do it? Especially giving information to people who simply do not know any better and try to sway their opinion because "I said so" or based on so and so's Theory with a bunch of neat little graphs (That only a handful of people on here will understand anyhow) trying to make them believe everything is true? Because if you have graphs and theory it must be true no matter what right?

Yeah...i've got a drag boat that'l turn 14,000 rpm and do 132.56mph in the 1/4 mile...i'll sell you one even if the biggest body of water around you is a swimming pool. Because...everybody needs to know that my boat will turn 14,000 rpm and do 132.56mph in the 1/4 mile. Everybody else should have one and it should do it to...even though they'll never really use it. It sure sounds cool!

Or better yet..I bought a Indy car last week...I was going 160mph down I-10 and decided to take it off road...it didn't work out so well. But the salesman told me that this car would do anything I wanted it to do?

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

IIRC most of it got started because people were posting in their "reviews" (I use that term loosely here) that the driver performed poorly in the upper end of the subbass/lower midbass region. So John provided information on the design and performance of his drivers, indicating that they perform suitably well beyond their intended range of use and well beyond the "problem area" these people were indicating. Thus the driver is not the problem but there must be something else at play, and these people repeatedly ignore his suggestions on what other issues could be causing their problems.....instead they are happy to just blame the driver and move on.

I don't know why you have a hair up your butt and are so dead-set on arguing with John. I guess maybe you're just upset that someone replaced their Fi with an AV and like it better //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[John_E_Janowitz 10+ year member]

It has everything to do with size and mass at higher frequencies. If it had nothing to do with it then Why do you even have smaller tweeters? Why do you have midbasses?

Directivity. The larger the diameter the driver, the more directional it is. In designing any system you need to pick your required coverage pattern. You don't always want extremely wide dispersion but may want high SPL capability. A recording studio would be a good example. You don't want reflections off the walls, etc. It's all about what is appropriate for the system and understanding your goals.

Every single person would use 1 12" full range driver, in each kick panel, and it would sound phenominal, and respond within +/- 3dB from 20-20kHz. (Which is comical in and of itself to achieve this "flat" response that when you finally hear what a "flat" response is...it honestly sounds terrible to the vast majority of the population)

Many people swear by high end "fullrange" drivers like the Feastrex as the best drivers on earth. The difficulty is that by the time you get to the upper frequencies your listening area is about the size of a pin point. Obviously this is not desirable for most anyone.

I agree, flat response is not what many people want. My goal is to create a driver that will accurately reproduce the signal input to it. This means low distortion and flat response coming from the driver. It is then the job of the person building and designing the rest of the system to control how that driver is used. In most high end installs whether it is a car, church, home theater, recording studio, etc I will setup the whole system so that the response is flat. Then I lock that portion of the system out so there can be no changes made. The user then has another set of EQ that controls the input to the whole system. They can boost bass, treble, cut certain frequencies, etc to their own desire without altering the way the system was setup.

You are getting distortion from the cone deflecting and becoming excited (amongst other things)... ie: the 'nodes' that are in the cone that i said to put on the shaker table and analyze via the accelerometers.

Yes, and paper cones have breakups as well. If you notice I have nothing against paper cones. Our TD woofers all use paper cones. When you start talking about getting up into the midrange and up to 2-4KHz, paper is clearly superior. For a woofer though, the aluminum works just fine and looks nice as well. I'm also able to create some jobs here in the US by having people working on them, which at this time in our country is a good thing.

It's easy to make a speaker have low inductance..that's great that you can do it. The Lambda (sorry if I spelled it wrong) is a great motor that does preform as stated. However...at the end of the day it is nothing more then copper rings inside of the motor, anybody can do that.

Anybody can yes. Does anyone else do it the way we do? Since 2001 when the first Lambda drivers had come out I hadn't seen another do it. It's not about doing something that others aren't doing. It's simply executing what you are doing properly. Likewise, I have no doubt that Fi makes great woofers. I don't believe I've said anything bad about them. The few times I have talked to Scott he has been knowledgeable and respectful. At the same time though I could state the same that anybody CAN do what Fi is doing as well. The fact is they aren't doing it and Fi executes very well.

I can make a speaker that has 150tm of Bl...and relatively high inductance, and will still be on par with what Wiggins is talking about with respect to "Impulse Delay".

Absolute levels have no bearing on the measurements. No matter what your starting point, you can take that same driver and if you add inductance the delay increases. If you subtract inductance the delay decreases.

But when it comes down to it where is the subwoofer mounted in the vast majority of cars? Do you think that ~3ms delay time you are actually going to hear? When you have a group delay of 10-12ms for the wave form to come from the back of the car..up to the front...where you are sitting in the seat...without being able to locate the woofer in the car and it blend phenomenally with the front stage being crossed higher than 100Hz?

You are clearly not understanding the paper so I suggest you go read it. I do agree that positioning is very important, and you have proven a valuable point. Moving a box around in a trunk or back of an SUV can account for a 3ms time difference depending on where you have the box placed. One milisecond is approximately equal to 1ft difference. So as you know, this difference can shift around the point at which the sub and front stage will cancel. While one woofer with a given inductance could have a cancellation up over the crossover frequency where it is not a factor, another woofer with a different inductance could have that same cancellation down in the operating range.

Theory is great...when you apply it and you actually start doing things and really sit down and think about it...there is a reason why it is all still Theory..and not a Law of Science.

There are some very imporant LAWS of physics that come into play with everything we are talking about. Specifically regarding inductance is Faraday's Law of Induction.

http://en.wikipedia.org/wiki/Faraday%27s_law_of_induction

It is not a theory, and the use of a shorting ring to lower inductance is also not a theory.

John

 

[NDMstang65 10+ year member]

IIRC most of it got started because people were posting in their "reviews" (I use that term loosely here) that the driver performed poorly in the upper end of the subbass/lower midbass region. So John provided information on the design and performance of his drivers, indicating that they perform suitably well beyond their intended range of use and well beyond the "problem area" these people were indicating. Thus the driver is not the problem but there must be something else at play, and these people repeatedly ignore his suggestions on what other issues could be causing their problems.....instead they are happy to just blame the driver and move on.
I don't know why you have a hair up your butt and are so dead-set on arguing with John. I guess maybe you're just upset that someone replaced their Fi with an AV and like it better //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

Nope not a bit upset, doesn't matter to me...I agree with John in that they were definitely abused, I never said anything outside of that.

Everybody has different tastes....well aware of that.

I'm not arguing..if i were arguing I would be upset...I'm simply asking questions as to how all of this does apply to the final scenario...in a car..or a home, and Can one actually hear it?

 

[NDMstang65 10+ year member]

Directivity. The larger the diameter the driver, the more directional it is. In designing any system you need to pick your required coverage pattern. You don't always want extremely wide dispersion but may want high SPL capability. A recording studio would be a good example. You don't want reflections off the walls, etc. It's all about what is appropriate for the system and understanding your goals.



Many people swear by high end "fullrange" drivers like the Feastrex as the best drivers on earth. The difficulty is that by the time you get to the upper frequencies your listening area is about the size of a pin point. Obviously this is not desirable for most anyone.

I agree, flat response is not what many people want. My goal is to create a driver that will accurately reproduce the signal input to it. This means low distortion and flat response coming from the driver. It is then the job of the person building and designing the rest of the system to control how that driver is used. In most high end installs whether it is a car, church, home theater, recording studio, etc I will setup the whole system so that the response is flat. Then I lock that portion of the system out so there can be no changes made. The user then has another set of EQ that controls the input to the whole system. They can boost bass, treble, cut certain frequencies, etc to their own desire without altering the way the system was setup.

Yes, and paper cones have breakups as well. If you notice I have nothing against paper cones. Our TD woofers all use paper cones. When you start talking about getting up into the midrange and up to 2-4KHz, paper is clearly superior. For a woofer though, the aluminum works just fine and looks nice as well. I'm also able to create some jobs here in the US by having people working on them, which at this time in our country is a good thing.

Anybody can yes. Does anyone else do it the way we do? Since 2001 when the first Lambda drivers had come out I hadn't seen another do it. It's not about doing something that others aren't doing. It's simply executing what you are doing properly. Likewise, I have no doubt that Fi makes great woofers. I don't believe I've said anything bad about them. The few times I have talked to Scott he has been knowledgeable and respectful. At the same time though I could state the same that anybody CAN do what Fi is doing as well. The fact is they aren't doing it and Fi executes very well.

Absolute levels have no bearing on the measurements. No matter what your starting point, you can take that same driver and if you add inductance the delay increases. If you subtract inductance the delay decreases.

You are clearly not understanding the paper so I suggest you go read it. I do agree that positioning is very important, and you have proven a valuable point. Moving a box around in a trunk or back of an SUV can account for a 3ms time difference depending on where you have the box placed. One milisecond is approximately equal to 1ft difference. So as you know, this difference can shift around the point at which the sub and front stage will cancel. While one woofer with a given inductance could have a cancellation up over the crossover frequency where it is not a factor, another woofer with a different inductance could have that same cancellation down in the operating range.

There are some very imporant LAWS of physics that come into play with everything we are talking about. Specifically regarding inductance is Faraday's Law of Induction.

http://en.wikipedia.org/wiki/Faraday%27s_law_of_induction

It is not a theory, and the use of a shorting ring to lower inductance is also not a theory.

John

I never said that Faraday's laws of induction did not apply i'm well aware of what it is and what they are...as they are called Faraday rings.

I asked the question, How does this impulse delay due to inductance apply in a car, in the real environment, not in a lab? Also...can a human actually hear it? I can't remember how fast the brain processes sound from the ear drums into signal as knowing this is a "Helicopter" sound.

Which is why I suggested the Indy car....I bought it...salesman said I could drive it anywhere so I hung a left turn going 160mph off of the road into the rocks off road...it didn't fair so well.

What I am asking is...how does that lab data apply to the scenario that the speakers are actually in?

 

[kendogg 10+ year member]

IIRC most of it got started because people were posting in their "reviews" (I use that term loosely here) that the driver performed poorly in the upper end of the subbass/lower midbass region. So John provided information on the design and performance of his drivers, indicating that they perform suitably well beyond their intended range of use and well beyond the "problem area" these people were indicating. Thus the driver is not the problem but there must be something else at play, and these people repeatedly ignore his suggestions on what other issues could be causing their problems.....instead they are happy to just blame the driver and move on.
I don't know why you have a hair up your butt and are so dead-set on arguing with John. I guess maybe you're just upset that someone replaced their Fi with an AV and like it better //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

You apparently haven't read all the threads then. So you're saying that those of us who did what he said, bought into every line of everything he said, and designed our enclosures WRT his inputs, and then got told we did everything wrong and it's OUR FAULTS the drivers drivers didn't perform as intended, should just STFU and bow out and let everybody else continue to be misled into buying drivers that will not work for them?? I think not sir.

Just wait until you have a problem and post your problem publically. Papermaker had John's full backing when he was supporting the driver. Once papermaker started actually using the sub, and realized what it's issues were (especially once the suspension broke in and softened up), he was ousted by John and berated as well. You'll see man, is all I have to say.

 

[microhaxo 10+ year member]

Wait a min here.. Papermaker fed the sub 1600w and Destroyed it and john gave him 200 dollars back.

Dont mislead people. My sub performs just fine and I've ran it two days straight. Same time papermaker ran his. Im pretty sure the only reason why his broke was that he was giving it too much power.

Also there has been No complaints from the home theater community where they run the subs at 1000w on extremely low frequencies.

You either just got a bad batch or didn't properly set it up. These subs may be more delicate than all out car subs.

Also to NDMstang65, i hear a difference real world between this driver and MANY others. So i don't know what made the difference but it is noticeable and audible to my ears..

 

[ciaonzo 5,000+ posts]

I'm beginning to appreciate my apparently rare and unique occurrence as an individual who not only loves wideband, low Q, low inductance, drivers with soft suspensions, but also knows how to use them within their limits and extract all the performance they have to offer.
Some of you should be thankful John is even taking the time to humor your responses. Especially when you tell him that you haven't even read what he's had to say, let alone try to learn from it, but you'll certainly argue back with little to no experience as a designer or even a small understanding of driver parameters. Obviously this statement does not include everyone who has contributed to this thread but for those who are taking exception to what I'm saying right now, you should read and try to comprehend what John is giving you which is basically a free lesson in driver performance regarding certain things.

It's a shame that he has to come here and defend what he is obviously very good at doing because of one or two people's misuse of a product that was not intended for the abuse it suffered. I've followed all of these threads concerning AE products and John has been very forthcoming and transparent with his very thorough explanations, mostly to people who don't understand it or appreciate it, and from what my experience tells me, he has been right on every account. And I know a few things. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

It's time to show this man some respect and end the smear campaign. Every company at every point has had some type of failure, whether it was a flawed design that went out and had to be used for a given period of time to expose the flaw, or whether it was simply a fluke such as a bad part or a less than thorough QC. The important part is taking note of these problems and doing what is necessary to make things right. This might involve recalls or replacements, further R&D, and public relations, or in this case, crowd control. Point being is that John is taking on that responsibility and yet you're continuing to attempt to discredit his efforts and his products. Shameful.

I just felt very strongly about reiterating this.

 

[John_E_Janowitz 10+ year member]

You apparently haven't read all the threads then. So you're saying that those of us who did what he said, bought into every line of everything he said, and designed our enclosures WRT his inputs, .

You did listen to part of what I suggested. However when it came time to moving the enclosure or adjusting the phase with respect to your front stage you refused and said that "I shouldn't have to do that much work." Keep in mind that I spent literally hours talking to you about many things but you didn't follow through on what would have given you good results.

Listening to part of what someone tells you to do will often get you disastrous results. If you were to go sky diving, got in the plane, put on the backpack, did everything they said, but forgot to pull the parachute open when they told you, look where you'd be.

Again, go back and read the things in this thread and the others. I clearly explained why you had the upper end issues, how to correct them, and potentially why this other driver doesn't have the same issue at the same frequency due to phase differences.

John