cdcool1
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Registered: 9th Jun 02
Location: Scunny
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My dad works at a builders merchants, so i can get more or less whatever i want. looking at a 1000W RMS sub in the summer, so just starting planning the install at the minute. is the stronger the wood the better? i know most people seem to use MDF, but i just want to know what the best stuff is, as i want the most out of the install.
cheers for the help
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Sando
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Registered: 24th Feb 04
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18mm MDF.
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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u want lightwieght, but highly rigid - no flexing - if u want an amazing material u want a bi-axial plywood - would flex and u wouldnt need it so thick either - so u could make a lighter install for the same properties as a much heavier MDF install
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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MDF is probably easiest to work with tho - and can sand to an almost glass finish once sprayed up
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T5POL
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Registered: 22nd Mar 01
Location: Fife
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Birch ply-wood. Its lighter than MDF and has better acoustic properties than MDF. You do not need to put fibre-fill in the enclosure when you have the exact dimensions of the enclosure specified by the manufacturer.
[Edited on 01-03-2004 by T5POL]
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cdcool1
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Registered: 9th Jun 02
Location: Scunny
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so birch ply-wood would be better? i'll look into the price of it.
what do products like dynamat and brownbread do? do they reflect sound waves or absorb them? if they reflect them, would it be an idea to line the box with something like dynamt to improve the properties of the wood?
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T5POL
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Registered: 22nd Mar 01
Location: Fife
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I done a few searches and there are so many different types of plywood out there. most people on other forums have mixed views.
Birch plywood is lighter but it is harder to work with. it is more expensive than MDF but it has a higher resonant frequency than MDF.
Here is something I took off of a forum called speaker asylum that I found.
Well, one of the advantages of MDF for most loudspeakers is that it has a low FS (resonant frequency), so the energy from the mids and highs tends to be absorbed or reflected without exciting its resonant modes. MDF is a good choice for most speakers. But no-void plywood has higher stiffness (good), but also a higher resonant frequency, so some frequencies produced by the midrange or mid-woofer will cause it to resonate more easily (bad). Now, for a sub, it is the opposite. MDF that is extensively braced is not a bad choice for a sub, but the low FS of MDF will mean that its primary resonance tends to be in the bandpass of the sub's operating frequency. Conversely, no void plywood has a much higher FS that will NOT tend to be excited by the energy produced in the subs bandpass. And you can always use a bit of MDF bracing or some other damping material to eliminate even that small bit of resonance. Put it this way - 1 inch thick walls of no void plywood with a half inch sheet of MDF bonded to the inside & braced with some cross braces would be about as inert a cabinet as can be built for a sub. Much better than an all-MDF cabinet, no matter how well braced.
Alot of people mention a wood called Finland Birch ply which has no voids in it.
[Edited on 02-03-2004 by T5POL]
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kev_corsa
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Registered: 7th Nov 02
Location: Newport, Uni in Bristol
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quote:
Originally posted by cdcool1
so birch ply-wood would be better? i'll look into the price of it.
what do products like dynamat and brownbread do? do they reflect sound waves or absorb them? if they reflect them, would it be an idea to line the box with something like dynamt to improve the properties of the wood?
absorb 
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cdcool1
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Registered: 9th Jun 02
Location: Scunny
User status: Offline
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cheers mate, very helpful 
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