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Jim Weisgram Jim Weisgram is offline
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Default Lining a Speaker Cabinet

On Sun, 21 Jan 2007 06:32:28 -0500, "JGS" wrote:

We are building an entertainment unit for a client. He designed it himself
and did a nice job. He wanted the boxes that hold the speakers to be lined
with MDF.
Now that we have built the unit we have found that here is room at the top,
bottom and back of boxes (cabinets) for 3/4" MDF but because of the size of
the speakers there is only room for 1/8" (if it's even available) for the
sides.
Is 1/8" MDF going to make a difference? Is there another material to use?
Or the broader question, is MDF required / desirable at all.
Thanks, JG


What are the boxes made of? Plywood? Plywood will resonate more in the
midrange frequencies than MDF, MDF will resonate more in low
frequencies. Adding layers of MDL to stiffen the enclosure sounds like
it makes a lot of sense. I am not certain where to get 1/8" MDF and I
don't think it will stiffen appreciably.

I wonder, though, if you can add thicker MDF in part of the side
panels.

You can do a couple of other things. You can run bracing along or
between the side panels. I suggest NOT at 1/2 the height or width;
using a different spacing will effectively break up the panel into
smaller less resonate sections and the amount of resonance will be
reduced, and the resonance frequencies of each section will be
different and so not combine to a larger peack.

You can check out antiresonant Deflex panels from a source such as
Madisound
(http://www.madisound.com/cgi-bin/ind...7226 8.22629),
or perhaps Sorbothane (reputedly not as effective).

By the way, I see Madisound is selling a 1 edition-old issue of "The
Loudspeaker Design Cookbook" for $11 (normally $30) and if you
purchase some Deflex, I suggest you get one of those. It will no doubt
have some very specific info on speaker cabinet construction.