Speaker cabinet materials.

Just wondering what are some of the materials used in building cabinets for speakers? We all know of mdf and solid wood, but how popular is aluminum? Magico and Piega use it. Are there others that use aluminum? And what other materials are used? What about acrylic?
Acoustical wool and mass loaded vinyl is used inside, what else is used?
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.

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.
Cabinets are rarely made of wood....MDF is a good damped cheap material.

Contrary to popular belief - good heavy and heavily damped cabinets with bracing add almost no audible effect on the sound - apart from the acoustic suspension from the enclosed volume of air which does affect the driver damping and affects the driver selection.

Common cause of this popular belief - cheap light weight speakers with cabinets that "waffle" and do indeed affect the sound.
Check out Green Mountain Audio. They use cast marble cabinets that are supposedly extremely rigid. Their bookshelf monitors alone weight in around 50 lbs each! There is supposed to be nearly zero box loss contributing to an incredibly clean and coherent sound.
Check out Green Mountain Audio. They use cast marble cabinets that are supposedly extremely rigid. Their bookshelf monitors alone weight in around 50 lbs each! There is supposed to be nearly zero box loss contributing to an incredibly clean and coherent sound.
Djembeplay (Threads | Answers)

Even marble flexes. One of the first mods GMA made to the Diamante was adding aluminum ribs bonded to the inside of the cabinet to reduce flexing.
Green Mountain enclosures are cast using our proprietary Q-Stone (TM). It has a much different formulation than used in our Diamantes from 1993 to 1997. No internal braces are required. It is far more rigid, and with far greater internal damping. And yes, heavy too, which by itself has little effect on the sound.

Best regards,
Roy Johnson
Green Mountain Audio
Hey Roy,

Nice to see you on here. I'm excited about your new Eos line. I'm scraping my pennies together for a pair of Eos 1's... I'm hoping I can manage it by the end of July :).

Keep up the good work!

My comment wasn't made to disparage GMA in any way. I just wanted to point out, that a material that one would not think of as being able to flex/vibrate, can do so much to one's surprise. To GMA's credit, they found a problem and fixed it. I have great respect for their designs.
Bamboo laminate is used by Escalante and Ascend Acoustics. Ascend has a CSD graph of the bamboo cabinet to show how little resonance there is in the v-lam bamboo. Go to the last graph on Ascend Acoustics Sierra graph page to check it out.
I love my granite cabinet made Ridge Street Audio "Sason" loudspeakers. Every time I compare them to other speakers that use other types of cabinet materials, I swear the bass from the granite speaker sounds much more delineated and has quite a bit more harmonic character all throughout the bass regions. The imaging solidity and clarity in the treble are also beyond reproach. Is this truly a function of the granite material? I don't know for sure, but I can say without question that these speakers do many things that no other speaker that I've owned can do!..... (13 different speakers at last count)
Vandersteen Audio model Five As and Quatros offer a unique constrained layer Damping system in a sophisticated multi enclosure.

When John Atkinson of Stereophile magazine measured their cabinets he said they measured insanely dead.
All of this is important yet the most dead cabinet in the world set up in a room with heavy bass nodes can defeat the purpose
The Room compensation feature of a properly tuned Five a and Quatro further allows the efforts of all this work to be appreaciated. ((take a listen...

I just picked up a nice pair of concrete speakers, the Rauna Frejas. These are a very heavy smallish 2 way with about a 5' woofer and a soft dome tweeter. So Far I relly like these. Other vintage speakers in my collection include Large Advents, Microaccoustic frm2 & 2a, DQ 10 and 20, Vandy 2ce, Polk Sda, and belle klipsch. I drive these with assorted vintage ss and tube electronics.
We use aluminum, baltic birch plys, mahagony bambo plys sometimes MDF if it needs to be painted. Corian works good, I find acrylics do not. We use Deflex, acousta stuff, wool,cork, silicon, rubber and carbon fiber in cabinets depends on design goal. Sometime hard rock maple for cabinet bracing again depends on design.
I forget the name, but I've heard fairly thin laminated wood speakers. The motivation was to build them in the same way as a violin is made and they did a good job with piano. Almost dipolar with all it's resonance.

The Krell LAT-1 was aluminum, wasn't it?

I think we're going to see more speakers made out some form of molded synthetic or compound in the future. Should make production less expensive.
Ngjocky Keep in mind the cost of a mold only way a molded cabinet would be cost effective to produce is in mass. So look to China;)
I agree with the poster above
Granite cabinet's done right (Ridge Street Sason's)
it's like there is no cabinet all you hear is the music
Alan Wolfe from Magico believes that Aluminum is the best material to use for a speaker cabinet, YG Acoustics also uses airplane grade aluminum to build their speakers, but if you are looking for the most advanced, most inert cabinet on the market, look no further than Rockport Tech. No one builds a better "cost no object" cabinet than Andy Payor.

look at the measurements for these two Rockport speakers, performed by Stereophile.


as far as i have seen, they are by far the most inert cabinet Stereophile has ever measured. Much better than any Wilson or even the Magico, two companies that spend a lot of money advertising the quality of their speaker cabinets.
Was wondering if anyone has ever tried making cabinets out of glass? It's a rigid material and can be damped by coupling it with materials of different densities.
I think the Ballistic Ceramic (compression wrapped in Kevlar) of my Cerious speakers is an ideal material - it is rigid yet lossy, and requires no internal damping materials. Wrapping ones knuckles on the cabinet is fascinating - the impact from your hand is completely absorbed.

There is a quite a bit of information on their site about the materials used - and the cost is quite reasonable as well.
Pedrillo, Waterfall Victoria Evo is a speaker made of glass, looks terrific and has rave reviews in French Stereo magazine.
the website is waterfallaudio.com. You can see all reviews. Launch in US in may.