Posted by Paul C. on May 25, 2002 at 11:46:17

In Reply to: Re: is fir better than MDF for bracing? posted by steve f on May 25, 2002 at 06:40:42:

I like to run a diagonal brace across the back panel, and a diagonal brace on both sides. I glue and screw these in on edge. I also tie the back panel to the front, using a 1x4, usually near the top edge of the woofer hole. The woofer really shakes! The sides of the front panel, each side of the woofer hole, are usually well supported by the side panels. Ditto the bottom of the woofer hole. But the top of the woofer hole is weak, as usually there is cutout for a mid or high horn or other driver, and more distance to the top of the speaker box. The front to back brace really strengthens the box and helps stop resonances.

If a speaker box is large (I had spkrs previously the size of the 4 Pi Theater, 36"x24"x18") I use a 1x4 brace mounted on edge diagonally on the back panel.

My boxes are STRONG. No buzzes, no vibrations.

I do not use MDF but for indoor, home stereo speakers. For PA and other MI use, birch cabinet ply only.