Box design sketch (pics)

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frugal-phile™
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Ornlu said:
Should the rear one be off center?

All braces should be off-centre... the use of irrational numbers to create the ratios is a good tool... it is even better if you can make the braces oblique (ie dividing panels into trapezoids instead of rectangles). A brace that is in a position to wedge the mahnet against is also a good idea.

dave
 
frugal-phile™
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Ornlu said:
How much of a difference will it make? I mean, I thought that the 1/2 wavelength of anything a subwoofer produced would be too big for resonance/standing waves in the box anyway. It's just that centered they provide the most structural support.


That last is not true, an oblique brace will provide greater structural support

In the case of the panels, the internal pressure will cause the panels to start to move... if the brace is in the centre, you can actually increase the size (and "tune") the resonance because you are giving the energy a path of least resistance..

dave
 

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frugal-phile™
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Even at 16^3 a brace that pushes against the magnets is a good idea (and the most important one)... and if you are going to add a brace, off-centre is no harder (oblique certainly is i agree). Even a half inch makes an improvement. If you are doing it, and it is no harger, why not do it right?

Example below to just give an idea....

dave
 

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Ok, the center brace I was planning on having 1 inch towards the back because the front is double faced anyway. Why is the support on the magnet the most important? Just out of curiosity. I'd be afraid of it buzzing or transfering mechanical vibrations directly to the box.
 
frugal-phile™
Joined 2001
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Ornlu said:
Ok, the center brace I was planning on having 1 inch towards the back because the front is double faced anyway. Why is the support on the magnet the most important? Just out of curiosity. I'd be afraid of it buzzing or transfering mechanical vibrations directly to the box.

The idea is to spread mechanical vibration to all the panels... otherwise it is all in the weakest panel of the box... the baffle (even at double thickness)

Better yet is push-push (ie active vibration cancellation) -- i usually don't build without it any more.

dave
 
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