wab (03/19/83)
Is there any reason that speaker cabinets are made out of wood exclusively? Someone once told me it was due to the special resonance quality of wood, but I'm not sure if that's right. Could speaker cabinets be made out of stone? My grandfather is a rocksmith and interested in the prospect of such a project, but I don't want to committ my money unless I know that the speakers won't sound odd. I know this sounds weird, but it's not as bad as putting mayonnaise on woofers. Bill Baker teklabs!reed!wab
saf (03/23/83)
There have been many experiments using other than wood for speaker cabinets. Clay pipe, etc. has been used with sucess. The main factor seems to be low resonance. This lets out thin steel sheets of course. Another factor concerns standing waves in the enclosure, so you still have to worry about the aspect ratio as with wood. Finally, damping material is a must. David Weems has several books out on the topic of enclosure design and in one of the books (at least) deals with "unique" cabinet materials. I believe his books are published by Sams and should be easy to find. Don't forget a final problem: Your speakers are not likely to be very portable - of course this also makes them theft-proof! Steve Falco BTL Whippany, NJ
filed01 (03/23/83)
There is a wealth of material on speaker cabinet design in a book by G.A. Briggs. It covers speaker enclosures using your fireplace, block walls, etc. It was published in the 50`s, and may be in a good engineering library. Herman Silbiger
newman (03/24/83)
As far as I know, the desirable quality of a speaker cabinet is NOT its resonances, but on the contrary that it be as acoustically inert as possible (i.e. no resonances in audio range). The commonly used veneered particle board is quite good in this respect. Using stone seems a bit unusual (not to mention heavy) but I have read about subwoofer enclosures made of concrete, I think in Audio Amateur. As I recall, he had to reinforce the floor.
wjm (03/24/83)
The reason speaker cabinets have been made of wood is because wood combines
the necessary acoustic properties - be dense enough to avoid resonances,
be able to seal in air (in a speaker design like acoustic suspension that
requires it) - the necessary mechanical properties - be able to support the
drivers in the proper position, and be easily fabricated into the proper
shape - with desireble aesthetic properties (most people want something
in their living rooms which matches their furniture). Other materials have
been used (notably high density plastics in some inexpensive speakers)
with technical success but have not been well received since they don't LOOK
good. Technically, you could make a speaker enclosure out of stone or
cement, but you'd have to be careful about standing waves in the cabinet
(stone is a better acoustic refletor than wood), you'd better have a fork-lift
truck or King Kong handy to move them (and you though wood speakers were heavy)
and you'd better check your floor loads (or you might have 2 holes in your
living room floor and 2 speakers in the basement.
Bill Mitchell
Bell Laboratories - WH
----- News saved at Thu Mar 24 09:05:51 1983
The reason speaker cabinets have been made of wood is because wood combines
the necessary acoustic properties - be dense enough to avoid resonances,
be able to seal in air (in a speaker design like acoustic suspension that
requires it) - the necessary mechanical properties - be able to support the
drivers in the proper position, and be easily fabricated into the proper
shape - with desireble aesthetic properties (most people want something
in their living rooms which matches their furniture). Other materials have
been used (notably high density plastics in some inexpensive speakers)
with technical success but have not been well received since they don't LOOK
good. Technically, you could make a speaker enclosure out of stone or
cement, but you'd have to be careful about standing waves in the cabinet
(stone is a better acoustic refletor than wood), you'd better have a fork-lift
truck or King Kong handy to move them (and you though wood speakers were heavy)
and you'd better check your floor loads (or you might have 2 holes in your
living room floor and 2 speakers in the basement.
Bill Mitchell
Bell Laboratories - WH