Simulating 18sound 10nmba520 dogbox

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The purpose is to simulate different dogbox designs for the 18-sound 10nmba520. This is the driver chosen by Troels Gravesen for The Loudspeaker, The-Loudspeaker

First I use Winisd to figure out a critically damped box size, and its potential maximum sound pressure.

Box size is 11,39 liters. Filter parameters are shown in diagram. System power is 130 W, cone excursion is xmax at 150 Hz.

 

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First Hornresp simulation is a straight cylindrical dogbox of 500 square centimeters, 23 cm deep.

There is a nasty interference at 740 Hz

 

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Next out is a parabolic dogbox. How can this be worse?

 

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Next out is a conical dogbox. Very much like the parabolic

 

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The last simulation is an exponential dogbox. Even lower resonance

 

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These results are not what I had expected.

 

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With filling the simulations look much better

First out is the cylindrical dogbox.

 

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This is the parabolic dogbox

 

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The conical dogbox

 

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Exponential dogbox

 

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I have increased the filling to 500 mks rayls/m. Increasing above 500 has very little impact.

 

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New curves and hornresp record with an equally large exponential dogbox.

This design is better than the others. 110 grams of filling in a 11 liter dogbox seems reasonable.