We did do a psychoacoustical test of simulated diffraction which showed that higher levels and longer delays were more audible, so that's a data point.Do you have any support for this for this statement?

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- Thread starter mabat
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We did do a psychoacoustical test of simulated diffraction which showed that higher levels and longer delays were more audible, so that's a data point.Do you have any support for this for this statement?

Two plane waves are traveling along a straight wall. All of a sudden the wall becomes circular and the wave starts diffracting. As both waves and boundaries are just rotates versions of the other, the amount of diffraction is the same.

The second derivative, however, is quite different at both point where the wave starts diffracting. The curvature

So, shouldn't we minimize the (maximum) curvature?

The question is what’s the best approach for modelling a rectangular AMT diaphragm in AKAbak?

I know some believe that adding a waveguide to AMT, doe not have any benefit. I have done a significant amount listening with and without guides, and to mine and others that have heard them, the waveguide improves the dynamics and benefits room interaction.

These are 1st (red) and 2nd (green) derivatives of a circular arc. They will give a constant curvature but neither of those is constant by itself.

https://www.derivative-calculator.net/

This is the generalized OS for k=1 and k=2:

Hard to say, maybe k=1 gives a lower integral value in some metric.

(The lower the 'k' the more is the curvature concentrated towards the throat, but it's higher at its maximum.)

Hard to say, maybe k=1 gives a lower integral value in some metric.

(The lower the 'k' the more is the curvature concentrated towards the throat, but it's higher at its maximum.)

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No response from Faital?Since its interesting I sent query to their customer service. Lets see if there is an answer

btw. here is another profile from yesterday, quite similar performance with very different parameters.

Curvature is also different, so real world compatibility to a particular compression driver would differ. I have no idea which one would work better on which driver, although the BEM result is about the same.

Tom's version makes better back side with tmax, less interference around the onion I would guess its the smoother curvature when t gets closer to 1 and beyond, mine droops.

Curvature is also different, so real world compatibility to a particular compression driver would differ. I have no idea which one would work better on which driver, although the BEM result is about the same.

Tom's version makes better back side with tmax, less interference around the onion I would guess its the smoother curvature when t gets closer to 1 and beyond, mine droops.

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Yeah, smoothing the curvature further seems to reduce diffraction, DI is smoother without extra "boost", increased DI around 2kHz in the above sim labeled #27.

Whether this is a good or bad thing I don't know, little diffraction there helps increase DI to lower frequency with same diameter device which makes for more constant directivity. This is same profile as above other than few parameters tuned to smoothen the blue and red curvature lines in Desmos. DI ruler straight, but not constant of course. edit. added #27 graphs for easy comparison.

Whether this is a good or bad thing I don't know, little diffraction there helps increase DI to lower frequency with same diameter device which makes for more constant directivity. This is same profile as above other than few parameters tuned to smoothen the blue and red curvature lines in Desmos. DI ruler straight, but not constant of course. edit. added #27 graphs for easy comparison.

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Just curious - what software are you guys using to generate the images above?I have found something I quite like for the T34A, it is harder to get right than the B version. The simulation conditions seem to matter much more than I found previously.

View attachment 1176180 View attachment 1176181

As I try to learn, I've been generating FRD files via ATH, and then importing them into VCAD to view performance. I was just curious if the above app is a faster process.

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