Which material sounds better for speakers construction? Wood, Ply or MDF?

@bukirob,

For the majority of loudspeakers, the goal is to have cabinets that produce as little resonance as possible (or in the case of BBC designs - move the resonance away from the midband), that is the opposite of string instruments. Loudspeaker designers want their drivers to do as much of the work as possible, not the cabinet. An acoustic instrument uses the wood body to amplify the vibration of the strings. By your logic, loudspeakers should all be made of thin sheets of tonewoods, in which case the cabinets would produce as much sound as the drivers. One could definitely achieve some interesting colorations with such an approach, and they’d likely sound good with certain types of music, but it definitely wouldn’t result in a flat frequency response, nor would the music sound as intended by the studio engineer.

Your logic is completely flawed. Not only are hardwoods often weaker than wood composites for a given thickness, they resonate more, and behave differently depending on their orientation in the structure. They are quite simply a poor choice for speaker cabinets with the few exceptions of those that are purposely designed to color the sound.

THAT ^^

A loudspeaker is not a musical instrument.   

@helomech --

There's an aspect of poster @bukirob's post above that may not have received proper diligence, which is that of acknowledging how different cabinet materials invariably have actual and different sonic characteristics. The analogy to musical instruments in this regard isn't necessarily a way of saying that speakers should be build the same way, i.e. as obvious resonators that highly contribute to the overall sound, but rather that care in choosing the right cabinet material should be applied to speakers as well, considering the above mentioned. The argument that enclosures need to be as inert as possible doesn't equate into their total inertness by any practical measure, and so their inevitable contribution is still to be dealt with - while often failing to properly do so, not least by ear. Quite a few I've spoken to on this subject feel particle boards like MDF or HDF have a tendency to unnaturally deaden the sound acting as enclosures, certainly compared to ply- or hardwood, not unlike the way I feel drivers with a range of "exotic" cone materials seem to lack a sense of aliveness, organic quality and energy compared to paper cones. How many actually speak of the rationale for choosing particle boards with reference to their sounding good - be it either in virtue of sonic absence or presence? Most simply and blindly refer to them as being relatively "inert." 

Phusis,

Neutral sound is of course subjective, however, the majority of loudspeaker designers seek to reduce resonance as much as possible or lower it to frequencies where our hearing is less sensitive. Solid woods don’t suppress resonance nearly as well as composites. An open-baffle design is far more logical than a tonewood box if one wants uncolored, true-to-the-source sound, with little to impede the behavior of the drivers. It’s also worth noting that cabinet resonance is usually heard as distortion - typically a grainy midrange, not something pleasant and complimentary to the sound of the drivers.

If someone wants a speaker that excells at reproducing the sounds of a violin, then certainly, it might make sense to use solid Spruce. Speakers from the likes of Viking certainly don’t sound neutral to my ears, but I’m sure they’re a perfect fit for some listeners.

I suspect some here are simply operating on the logic that MDF and plywoods are inexpensive, therefore, they must be an inferior choice. This might be true if discussing dressers or coffee tables.

Please note, Magio STARTED their speaker manufacturing business using plywood for the cabinet . MDF is as dense as plywood and inert enough to adhere veneer without future movement. It’s inherent stability combined with bracing creates all the stiffness necessary for any speaker enclosure. Drivers are tuned to the box, therefore if aluminum were used, as it is stiffer, and more dense, the driver types, as well as other design components, will be necessary for tuning the sound. Finally, few can afford a 200,000.00 pair of aluminum billet machined speaker so it hardly matters if aluminum is a better material. I listened to a magico system, m project speakers, and my guess is that system was in the neighborhood of 350,000.00. Frankly obscene, however, after 20 minutes of listening, although the aluminum speakers had a provocative sound, they were very fatiguing to the ear. All sweetness was gone. The difference between theory and reality!!