Speaker cabinet materials.

I've seen a few companies that use precision molded concrete. I'm sure it stops resonance, but it is also difficult to work with and for a large floor speaker it makes the weight nearly unmanageable.

I remember some speakers from one of the "shows" a while back that used a concrete enclosure for the woofer, and an expansion horn created from trans-laminated hardwood for the tweet/mids. The stereophile writer said he wasn't even going to ask how heavy they were.

Joe

I have seen and have own speakers made of pure corian.

the best cabinet is no cabinet. wood resonates. perhaps, some inert matrial with such a low resonant point would be ok, but i suspect that it woud be very heavy.

Most speakers, as you state, use some type of wood product, mostly MDF. There are some like Rockport that use molded layers of a hard and soft materials to help damp resonances. Wilson uses layers of methacrylic and a damping material, and also a mineral-loaded phenolic compound. Some manufacturers such as Sonus Faber feel that since all cabinets resonate, they should be made of the same wood used in musical instruments. Others feel that the cabinet should be damped as much as possible to minimize its contribution to the sound. I guess it just depends on what type of sound you like.

I have been considering building some isolation platforms and devices out of a material that my company uses in our products for vibration dampening. The product that we use is a special steel that is comprised of one layer of 12 gauge steel, a layer of a dampening polymer and another layer of 12 gauge steel, heat/pressure laminated. Our supplier can provide this to us using Stainless steel on the outsides or cold roll steel, with a wide range of gauges. The affect on our equipment is a significant reduction in noise levels by eliminating vibration of moderate expanses of what would otherwise be ringing sheet steel.

Even with sections as large as 2.5 feet X 4 feet (10 square feet) the sound is virtually dead with a knuckle wrap on the sheets' center point. Certainly as dead as a similar knuckle wrap on my Wilson speakers.

We got this idea from BMW, they used this same material, that we have made here in the States to separate their engine compartments from the passenger compartments. It is a very effective product.