Subwoofer enclosure internal bracing

[rocko1290]

Just looking for a picture/description of the internal bracing of a subwoofer box, so I can get an example of how to do mine. Thanks

[Cal Weldon]

Hi Rocko,

I don't have pics but there are basically two type of braces. I will call them stick and panel. A stick brace is a piece of wood, let's say a 2X2 that you screw in place across any particular section.

A panel brace is one that is a piece of wood (panel) that fits tightly into the box and would act like a separator if it weren't for the holes cut in it.

Here's what came up when I googled internal subwoofer bracing. There are both types there.
http://images.google.ca/images?svnum...ng&btnG=Search

[rocko1290]

Originally posted by Cal Weldon
Hi Rocko,

I don't have pics but there are basically two type of braces. I will call them stick and panel. A stick brace is a piece of wood, let's say a 2X2 that you screw in place across any particular section.

A panel brace is one that is a piece of wood (panel) that fits tightly into the box and would act like a separator if it weren't for the holes cut in it.

Here's what came up when I googled internal subwoofer bracing. There are both types there.
http://images.google.ca/images?svnum...ng&btnG=Search

For a 350L what kind of bracing would I need?

It looks like they went a little overboard in those pics...

[Volenti]

Originally posted by rocko1290
For a 350L what kind of bracing would I need?

It looks like they went a little overboard in those pics...

No such thing as too much bracing

this is a 250L bandpass enclosure with appropriate bracing;

[Cal Weldon]

Very nice job Volenti.

[noodle_snacks]

I think a more realistic goal for bracing is to make the panel resonance high enough so that it is not excited by subwoofer frequencies. Bracing raises the stiffness of the panels, and hence their resonant frequency. However get the wrong amount of bracing and you might have a resonance around the crossover frequency, which would make the sub easy to localise. The bracing scheme used on the old adire tempest ported designs was pretty reasonable to me. I don't have a source but i seem to remember adire recommending the minimum bracing spacing just be kept less than a certain amount (for subwoofers)

[noah katz]

The most bang/buck is simple cross-bracing.

Use enough braces so that there's no more than 12" of unsupported 3/4" panel.

[rocko1290]

Can you kind of like just make a skeleton of the box out of 2 x 2 boards? Would that be sufficient bracing?

[rocko1290]

Also, is there a problem with having an enclosure that is perfectly square?

[badman]

Square enclosures are typically not recommended as they tend to have resonance at single frequency (plus multiples of course). For subwoofers, usually, this fundamental is much higher than the passband so it's not much of an issue. When you build a 100 ft^3 sub enclosure, it would become relevant though