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Trey803
05-01-2006, 08:17 PM
I saw this on the internet. "Never build a cube shaped box, which is the absolute worst enemy of a smooth frequency response curve." Is that true? Does the shape of a sealed subwoofer box change the way that the sound is produced????

ballstothewall
05-01-2006, 10:24 PM
According to a study done in '51 by a Harry Olson, he found out the the difference in variations in accordance with the box sizes...

(all values are +- variations in SPL levels)
Sphere: .5dB
Cube: 5dB
Beveled Cube: 1.5dB
Rectangle: 3dB
Beveled Rectangle: 1.5dB
Cylinder: 2dB

"The rectangluar loudspeaker enclosure is, however, often judged less than optimal as a radiating surface because of edge diffraction issues and also less than optimal regarding internal standing wave modes."

I am pulling this info outa my Loudspeaker Design Cookbook, so take it for what its worth...

Volenti
05-02-2006, 09:27 AM
Actually a sphere is the "worst" as far as standing waves is concerned, however at bass frequencies the wavelength is too long for standing waves to form in the enclosure unless the longest dimention reaches 1/4 wavelength of a frequency in the bandwidth in question.

In english, it doesn't matter unless the box is really large/long. (4'+)

Because of this a cube or sphere is an ideal shape because of the material strength advantage these shapes have.

swimfreak26
05-02-2006, 12:26 PM
^^There's your answer.

Standing waves FTL, which is what you have a bigger problem with in cubic and spherical enclosures. As stated though, bass wavelengths are quite long, and getting to 1/4 wavelength take a rather large box. So, a small cube shouldn't hurt anything.

azbass
05-02-2006, 12:32 PM
a cube or sphere is an ideal shape because of the material strength advantage these shapes have.

orly?