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

Plywood is superior to solid wood and MDF. It has superior resistance to bending forces and a better strength-to-weight ratio. That is why it was used for aircraft during the "wooden plane" era! My vintage JBL C35 and C38 cabinets used plywood, along with my Altec Valencia's, Klipsch Heresy's and Rogers LS3/5A's.

Possibily marine grade plywood?

Amongst hardcore DIY speaker builders, "Baltic Birch" is considered the best plywood. It is void-free, 13-layer 3/4", often in 5' x 5' sheets, though sometimes 4' x 8'. A great enclosure can be made of an inner box of Baltic Birch (with cross-braces also made of BB), surrounded by an outer layer of MDF, with a thin layer of constrained layer damping material (such as E-A-R Isodamp) between them.

MDF first then veneer, not plywood. Almost all plywood has core voids, even pricey Baltic Birch. Unless you specify all B grade veneer, but even those will have defects in the veneer faces.
B&W uses wood veneer sheets to build their enclosures, probably 1/10" or less, maybe even 1.5mm sheets, so yes using 12-13 sheets will get you 19mm or 3/4" close. Using veneer sheets allow them to bend the form to create their desired shape.

MDF is homogeneous, same density from face to back, all throughout, no core voids. Can be moulded and shaped easily, painted and or overlaid with wood veneer and stained for a super high end finish. The boxes using MDF are perfectly matched meaning both speakers will be identical to within set tolerances of probably +/- .03125".

I think it's close between ply and MDF. Construction matters however.
The best MDF I have seen use 1" thick layers to build up the case, with each layer using a different bracing topology. This yields an incredibly stiff and inert cabinet. but is very expensive and produces tons of dust.

Best left for those with access to CNC machines. Still, it's a lot cheaper than billet aluminum. :)

Best,
E

Try Magico they use aircraft grade aluminum as it sounds much better and is neutral.Mdf is history for state of the art speakers.

we made some speakers from   Bamboo 1 ply, 
the very solid material  ,and good acoustic performance 

There is no absolute.  
MDF is more dense than plywood or wood.  Wood on its own depending on type has all kinds of problems with expansion and contraction.  Plywood works, but still is a softer less dense material... However, if you are after an effect,  plywood can be more giving than MDF.. Also, the is no problem with gluing MDF & Plywood together, this works.  Way back when,  we built a cabinet out of concrete & ground up Styrofoam, worked great.  Also a few decades ago, I believe Definitive made some concrete enclosures.  

I built a pair of back-load horn single driver speakers last summer using the Madisound BK-16 kit design but modified it a bit and doubled up on the baltic birch side and top/bottom panels in the enclosure. The back panel and the front baffle were already double sheets. They came out great and sound real good with decent bottom end but took weeks to break in. I would have put some damping sheets between the panels but I learned about them after it was all done. May be next time. I may be old school or an amateur but I never warmed up to MDF except for shelving in my closet.

My Audio Note speakers are built of baltic birch ply and sound fantastic. They seemed faster then other speakers I listened to at the time maybe the cabinet material came into play.

Building a PROPER cabinet for speakers is more complex and costly than dipoles, and dipoles tend to throw a more realistic sound stage. I know this from owning Genesis V loudspeakers (to its credit, it did have a rear firing tweeter) Usher 6371s, First Gen  Reference 3A DeCapos, a short stint with Nearfield Acoustics entry level Pipedream 6 ft prototype, then moved on to Accoustat 2 + 2s, Magnepan 3.5Rs (and even though they had their own magic, both physically dominated my room. for the last couple years, I have been enjoying Emerald Physics KCIIs, which are as light and fast as the 2 previous dipoles, but the KCIIs bring better bass and more focused imaging, AND, they're super efficient. The amount of wood and the simplicity of assembly is something a DIYer should consider. 

A combination of materials are good - on most of our speakers we use a solid hardwood front up to 2” thick depending on model - with a heavily braced rear enclosure typically made from 1” thick MDF 

As with anything implementation is equally important

Good Listening

Peter

Material "X" and material "Z". Wilson Audio.

Baltic Birch ply -Russian birch ply 1-1.5inches thick on the front baffle 
1inches everywhere else, 2inches on the platform braces acoustic glues 
and real wool felt on top drivers , back baffle ,sides
acoustical foam on Bass. The Balticvariety ply like a laminate absorbs sound well ,and Baltic Birch from a colder variety climate the wood is denser . And like a wood instrument sounds even more musical when done right , time consuming ,and more expensive 
but worth it .Justgo to his site he builds  customspeakers around the world well into the $$ 1,000s.

i have made my own and worked with great speaker builders such as Tony Gee, who does all themajor Capacitor Xover reviews
under Humble home made Hifi . I learned a lot from Tony
10 years ago when I ran a Audiostore in Europe.

+1 peter.
I've wanted to play with composite sandwiches, as well as using layers of the same materials with different cut-outs to prevent panel length resonances.

I am quite keen on Panzerholz, a very dense, very dead German beech plywood with elastic properties. Costly to experiment with, though - $1000 sheet.

MDF and plywood are okay. HDF is better. Wilson uses variants of quartz and Corian countertop material. 

All sorts of composites and plastics can be ordered in sheet form from McMaster in various thickness. Methacrylate acrylic and phenol works great.

Bracing is very important. Isodamp is amazing stuff.

I would stay away from aluminum. Goldmund, Magico, and YG lost their minds. It's the worst material for a speaker enclosure.

Love aluminum Magico already sold out the first run of A1 speaker at $9800.00 pair so there are many people that love aluminum.It also depends on drivers and crossover in concert with  aluminum and yes Wilson speakers are also wonderfully made.

You've got to wonder about the motivation of a high percentage of those buyers.  They're people impressed by the Magico aura, who until now couldn't afford to own the brand.  But that's the point: they're buying the brand, not the sound.

Most materials can be made non-resonant/acoustically inert, when(as mentioned above) implementation, bracing, and thickness/layering are given proper attention.  Fiberboard also comes in a variety of densities(not just MDF).  https://en.wikipedia.org/wiki/Fiberboard

@ebm 

The A1 is a much much better value and realistic speaker to live with than the S1 Mk II , so I'm not surprised. 

Important to note, that it's easy to make fewer speakers than you think you will sell, so you can later announce you are sold out! Generates great hype. 

Having said that, while I do think Magico's are overpriced in general, they at least have some of the smoothest frequency responses, with consistently great dispersion in a "high end" speaker I've heard. They are one of the most consistent sounding "high end" speaker brands. I think they tune a little bright, and that the prices are astronomic, but otherwise not bad speakers.

Best,

E

I agree the A1 is much better than the S1 mk2 having heard both at Axpona this year.I love the Magico aura been in the hobby 50 years i have had many speakers including the Magico mini 2s made out of layers of Baltic Birch one of the best made wooden speaker cabinets.With the Magico aluminum  cabinet you must get the best amp and  preamp also you must use the best copper speaker wire.I have had Maggies 1Ds mg 3s  and Avalon to name a few.I don't clam to know everything but i have learned a few things  over the years.It however takes a lot of effort to make Magico sound its best.I totally agree there are many great speakers out there of which Magico is just one.Overpriced is not a problem for me however i never paid list price on any speakers.What great speakers do you have?Good luck in this great hobby.

3 things make a great speaker the cabinet,the crossover and the drivers of which Magico makes the cabinet and most of the drivers not the tweeter however.Oh well thats my opinion.Good luck.

My Italian walnut diapasons sound pretty good. I’m voting for solid wood. It’s just too expensive. Walnut, maple and cherry is very dense but to build a speaker cabinet it’s just too expensive. 

Of the same thickness, MDF is the least resonant and most neutral. Like bamboo and solid woods, birch ply boxes tend to impart a sound signature - typically a leaner, brighter sound than MDF (to my ears).

Weird that aluminum is brought up in a thread about wood derivatives. Aluminum (even "aircraft grade" alloys) will ring unless very thick and carefully braced. 

My Magicos do not ring as they are braced big time and they are very thick.

@ebm

What great speakers do you have?Good luck in this great hobby.

I design my own. Here is what I’m listening to now. The tweeter is the same as used in some Gryphon designs, the mid-woofer I’ve seen in Wilson and other speakers:


https://speakermakersjourney.blogspot.com/2017/12/snr-1-two-way-high-end-diy-monitor.html


Caps are top of the line from Clarity, resistors from Mills and copper foil inductor in the woofer. Not sure if it’s Mundorf or Jantzen. Cabinetry is from Lee Taylor

@ebm You better believe it they ring like a bell! No matter the bracing. You can't just knock on them as a test. You need a tone generator and vibration measuring tools. 

Take a look at Stereophile, every review of Magico omits this test, but all other speakers have it. There's a reason for it. 

Thanks for your bogus opinion mr Stereophile.What great speakers do you have???

ebm@  you right, The Magico , YG is not stupid, The harder material
get less  vibration , The harder wood, bamboo also better them MDF.
In reality  good braced  MDF is also good enough, The conclusion
if you  gonna spend more money--- best choice -aluminum , next
solid wood  and   last -MDF 

ho ho ho..ebm doesn’t think his speakers ring.  This is very important!   😉

If they do it sounds great to me and many Audiophiles who have heard them.Thanks again I'm sure your speakers are great as well.Thanks again.

@bache,

https://www.bbc.co.uk/rd/publications/rdreport_1977_03

Here is what I would say about that.  How many CONCERT level instruments are made out of plywood or MDF?

Answer = 0

While a speaker is not an instrument in the sense that you can play it, it shares ALL of the concepts of a device, usually some type of chamber in which sound is projected for the audience to hear and enjoy.  

It would seem to me that Wood would be the obvious choice. 

@bukirob What sort of logic is that? 

buki is exactly on point here:

Here is what I would say about that. How many CONCERT level instruments are made out of plywood or MDF?

Since I listen to mainly jazz vocalists my speakers are made mainly of deceased jazz vocalists. You would not believe how long I waited for this pair. Touch and go for a while, I was worried the singer might recover.

Doesn't Harbeth use solid wood for its cabinets?

^ They use relatively thin MDF panels, veneered on both sides. I believe a couple of their models use a combination of ply and MDF.

Here is what I would say about that. How many CONCERT level instruments are made out of plywood or MDF?

Answer = 0

While a speaker is not an instrument in the sense that you can play it, it shares ALL of the concepts of a device, usually some type of chamber in which sound is projected for the audience to hear and enjoy.  

It would seem to me that Wood would be the obvious choice.

If the goal is to hear the resonating wood (as is the case with string instruments), then yes, solid woods are certainly the best choice. If it were the most inert and neutral material choice, we wouldn't have such large variations in the design of string instruments. Any experienced guitarist can tell you that sitka spruce and maple sounds brighter than mahogany. Hmmm...ever wonder why the call them "tonewoods?"

Further, as mentioned in the white paper linked above, solid woods are not isotropic. They also have too many inconsistencies in terms of density and grain patterns - even with cuts sourced from the same tree. This is why no two string instruments - even from the same luthier - will sound exactly the same. These issues could create problems for pair matching of speakers.

@invcitus005  

You clearly do not know much about the live concert instruments.  I can not think of a string instrument that isn't made out of wood which is UNIVERSALLY individually selected.

For example, PRS guitars have 2 distinct level (this is very common among concert level instruments) General line, of which some are made in Korea and the remainder are made in the USA.  Then there is their private stock line where the woods are individually selected for their tonality SPECIFICALLY.   

That last word explains my VERY sound logic Invictus.  Woods have tonality properties that NOTHING else will reproduce. SOME have exceptional resonance qualities and these are selected by luthiers.  You know its why a Martin D45 that was made in 1941 is for sale for $350,000.00.

Its also why a 1957-1965 Les Paul sell routinely for $100,000-325,000.  New these guitars would have sold for $300-500.  I purchased my 1974 Les Paul for $350.00  Today, its worth 10 times that much.  As it ages it will continue to rise in value.

Anything that is resonating sound, AKA music, the type of wood matters.  The idea that wood vs MDF/Plywood doesnt matter is utterly absurd.  Sure you are going to pay through the nose for wood but it is a FAR superior choice.   

Just a guess, but Im betting these arent made of MDF or Plywood.

 https://www.audiogon.com/listings/lis8jgf6-cessaro-liszt-horn-speakers-full-range#&gid=1&pid...

@bukirob I clearly know all about the musical instruments. However, I have a hard time comprehending your backwards logic. It’s clear you don’t have the slightest idea on how good speakers are and should be built.

@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!!

Listen to my Q3s for hours and never get fatigued.It depends on the wires which should be copper and the electronics it took me years to get them to sound my best.Oh well everyone has a Magico negitive rap.Enjoy the hobby!!