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Discussion Starter #1 (Edited)
For test setup, procedures, and information on how the data was obtained see sticky here:
http://www.diymobileaudio.com/forum/product-reviews-erin-harrdison-bikinpunk/103414-driver-testing-methods-setup-frequency-response-harmonic-distortion-only.html
Do not ask setup questions in this thread. This thread is only for driver discussion.

To understand how to read the data, try here:
http://www.diymobileaudio.com/forum/product-reviews-erin-harrdison-bikinpunk/103817-how-read-frequency-response-harmonic-distortion-plots.html


Driver Tested:
Audible Physics AR3K:





Impedance and T/S Parameters:



Frequency Response at 0 degrees, 3dB scale:


Frequency Response at 0, 15, 30, and 60 degrees, 5dB scale:



Harmonic Distortion at 89dB:


Harmonic Distortion at 92dB:
 

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Pretty nice impedance curve. No hiccups or bumps there. A zobel might help flatten it out when ran all the way up.

Kevlar is a bitch to work with. It is very rigid for it's weight meaning it is hard to damp resonances within the material. You can see this in the bumpy FR...probably some energy storage going on. The main resonance was pushed way up in the FR to where it likely would not be audible or a much of a problem.

The distortion plot shows the resonances being propagated through out the distortion profile. With F3 being above F2 you might find this to sound detailed, aggresive, or have some bite in the upper midrange/lower treble. F5 is a little high in the 1-2k range which might enpart a sense of detail or fowardness in the midrange. This guy might need a tweeter around 4k if you are bothered by this.

A nice little driver with a bitch of a cone material to work with.

Your miles and experiences may vary...lol.
 

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Jason,

Care to hazard a guess as to what is causing the 12db peak at roughly 12khz? For a cone of this size and material is that likely to be cone breakup? It just seems to be very pronounced (much more so than what you see with paper or poly - actually pretty reminiscent of what you see on the metal cones like the Seas W15CY001). I wonder how the rigidity of the kevlar compares with a metal cone...

TO BE CLEAR - this is not a dig on the driver because as mentioned the peak is very high in freq but I am interested in the causes. When I first looked at this I thought breakup but I am by no means an expert.
 

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Hearing at least two cars with these drivers in them in person they had fairly detailed sound. Actually, a little too sterile at times but two years ago that sound would have been perfect for me. I much prefered the warmth the xr3m had at this stage in my aural evolution. But still I could have without a doubt gotten them to my liking with my own tune. Good job Mark for bringing a driver in for the detail fanatics:thumbsup:
 

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"Authentic to the Music"
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Pretty nice impedance curve. No hiccups or bumps there. A zobel might help flatten it out when ran all the way up.

Kevlar is a bitch to work with. It is very rigid for it's weight meaning it is hard to damp resonances within the material. You can see this in the bumpy FR...probably some energy storage going on. The main resonance was pushed way up in the FR to where it likely would not be audible or a much of a problem.

The distortion plot shows the resonances being propagated through out the distortion profile. With F3 being above F2 you might find this to sound detailed, aggresive, or have some bite in the upper midrange/lower treble. F5 is a little high in the 1-2k range which might enpart a sense of detail or fowardness in the midrange. This guy might need a tweeter around 4k if you are bothered by this.

A nice little driver with a bitch of a cone material to work with.

Your miles and experiences may vary...lol.
You pretty much correct as this is the sound I wanted for this version of this driver.

Your correct again, dude you have no idea how hard it was to make the Kevlar sound nice and play all the way out without being to harsh that a little eqing or notch work couldn't fix it.

Once more I not the techy type and i'm still learning, But again this is what my designer said it would look like.

But most have found it to be very easy to work with and not need for a tweeter. Great post sir and Thanks for helping people understand what they see and how it relates to the sound.

Some would just see it and think the lower the better which is not true in all cases. All these driver was designed with listening and the measured. Sorry but it was:blush:

We just want two driver that was designed the same, but sound quite different. Something for everyone was the goal.
 

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I would take a guess and say it is probably a cone resonance. Kevlar is a tough tough material to work with...it has little to no internal damping. It (and carbon fiber) have less internal damping than most metals.

Have I said how much of a bitch composite materials are to work with? This is a pretty good (IMO) job at a kevlar cone. Really good.
 

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"Authentic to the Music"
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I would take a guess and say it is probably a cone resonance. Kevlar is a tough tough material to work with...it has little to no internal damping. It (and carbon fiber) have less internal damping than most metals.

Have I said how much of a bitch composite materials are to work with? This is a pretty good (IMO) job at a kevlar cone. Really good.
And you would be correct Jason it is a Break-up/resonance. We tested a few different Kevlar cones to get to the point we needed. It is not as bad as it it seems, it was kind of a solution.
 

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And guys please don't think I am saying something is bad because of this and that. Just understand what you like and use what you like. I happen to like that added bit of odd order stuff on things like acoustic guitar and classical music...I think it adds a since of realism to the music. And while there might be a bump here and there, keep in mind this is speaking in absolutes...but as we know the world doesn't work in absolutes. Chances are you may not hear any of this.
 

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"Authentic to the Music"
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And guys please don't think I am saying something is bad because of this and that. Just understand what you like and use what you like. I happen to like that added bit of odd order stuff on things like acoustic guitar and classical music...I think it adds a since of realism to the music. And while there might be a bump here and there, keep in mind this is speaking in absolutes...but as we know the world doesn't work in absolutes. Chances are you may not hear any of this.
Your correct once more sir and this is one of the strongest points of the AR design.
 

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Mark, you did a good job in the meat of the midrange with this guy. The area from 300hz to 2,500hz is especially clean. The high order distortion is even better than the low order, a proper tradeoff in speaker design. In fact, limited as such for pure midrange duty I don't see a better driver that Erin tested so far.

I figured after all the nitpicking I did with you, I should call out the strengths of the driver too. Of course, anybody can see how 2nd through 5th harmonics are roughly between -70 and -90 db (that is .03% and .003% distortion respectively). That's well outside my hearing capability. :thumbsup:
 

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I currently have a pair of these running in my garage. They are mounted in paper coffee cups with the backs cut out. The magnet is huge and almost doesn't fit inside the cup. I have a cardboard baffle in front.



This is the best garage sound I've ever had, and better than the planars in the background. The whole vocal range up to about 2500 hz is like butter, baby. The only major EQ tweak is taming a peak at around 3500 hz, and suppressing around 800 hz a bit for tonality. The supposed 10 khz peak does not stand out. The tonality is laid back and kind of tubby, in a satisfying way. All sibilance is completely gone; if anything, S's are too quiet.

They are pretty directional in the upper end, which makes sense for a wideband. The only compromise in my garage sound running the AR3K's is that there is a definite sweet spot, which is standing in the middle of the workbench. Walk around the room and the upper end starts to disappear.

Mark, when are you going to start selling these things on the regular? As far as I know there was one introductory XR/AR blast and then they were no longer for sale. I'm starting to feel like I own a collector's item.
 
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