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

 I was once in prison and made homemade speakers on the cell block for people... I used layers of hardback books to make the boxes and made my cones From drawing paper, used earth magnets and my coil wire I got out of the transformer in an alarm clock radio. I also built dual bridge rectifiers that I tied into the sound chip to double the power going to it. My voice coils were a total of 8 layers thick.. (4 coils)for one speaker... (2 coils for left channel and 2 for the right channel) but mono output.......... Not much to do in there so I spent my time learning .... Just sharing an experience...... 

Helomech, you make a lot of good points, well done.  

Its funny everyone gets caught up in cabinet shape, wood or not, shape etc, when the room you put the speakers in makes far more tonal difference than the cabinet.  AS you move up the quality and lower the noise floor some of these tiny differences like metal vs wood and other small details start adding up so they do matter.  But for most, at home or the studio, the room is the issue that divides great sound from just okay sound.  
Brad

@invictus... you clearly don't I am a professional musician  Not a single solitary vintage marshall or fender cabinet is made of plywood, MDF, or particleboard. They are almost exclusively made of Birch.  So you can flap your gums all you want but the actual fucking MUSIC is made with solid wood instruments, solid wood cabinets etc... END OF STORY

Logic. Never was your strong suit.

Most speaker companies will not build their speakers out of solid wood because the expense would be to high

poppycock. There are speakers that cost 500k. There are people that buy them. 

I really enjoy my solid wood (Sapele) speakers.  Most speaker companies will not build their speakers out of solid wood because the expense would be to high.  There is a correct way to build speakers out of wood which is very time consuming. I know there is more cost to a speaker then the cabinet.  But I couldn't spend 10's of thousands of dollars on a MDF cabinet with bondo filling the gaps. As for sound goes. Everybody has a personal preference no matter what it's made out of. Find the best speaker that plays the most genres of music really well. 

There are some who still feel that using MDF alone in a traditional cabinet is a tonal midrange killer. So naturally enough many other options have been explored, all usually costing far more than the readily available and cheap to work with MDF. Some cynics might argue that they were the only reasons for MDF becoming almost ubiquitous in the last 2/3 decades.

More recently composites have become increasingly popular. Peter Comeau, formerly of Heybrook, now working with IAG-owned brands like Wharfedale, Quad, Audiolab and Castle, has been studying cabinet resonances for decades, and now uses chipboard/MDF composite panels for his loudspeakers.

Harbeth stick with MDF / bitumen damping panels but their cabinets use a unique ’lossy’ construction which flies in the face of all those who favour high rigidity above all else. Harbeth also firmly believe in using veneer on both sides of the speaker panels - presumably to ensure long term stability.

Nobody yet has claimed to have been able to make those pesky cabinet resonances totally inaudible, and it’s difficult to see how they could, but the choice of where to put them will always partially depend upon what material you use to build your box.

Fans of panel or open baffle speakers will have to look for other things to worry about.

https://www.google.com/amp/s/zstereo.co.uk/2018/10/20/peter-comeau/amp/

When building my three way, triamplified all horn loaded DIY speakers I found a constrained layer construction of 3/4" marine plywood, 1/8" neoprene rubber and 1/4" aluminum to be a good choice for critical panels.

I prefer speaker cabinets made of ice if you can keep the listening room cold enough...otherwise you wind up with a wet pile of components on the floor and, seriously, nobody needs that.

Good quality MDF doesn't need finishing on both sides. You can leave the inside surface bare. 

Out of curiosity, as I am planning to build my first speaker soon, would MDF with a glued on Formica (smooth countertop laminate material) on the “inside” of the box work, or would the extremely hard Non-porous Formica cause too harsh of a sound?  I know I’d have to have some sort of sound batting or something inside also.

All companies believe they have the best approach.  Implementation still matters the most.  You can have the most inert cabinet, but if your speaker is bright and fatiguing or can't image or has terrible bass, it won't matter. 

Ton's of approaches to building a cabinet and lot's of great speaker choices.  We are lucky to be in a great age of audio where we have so many options.  

I hope it is OK if I ask this here, as search engine brought me here.  Do all these factors also apply to the foundation mounts for high end car audio woofers?  Specifically, which is a better material for mounting 6.5" Focal Utopia woofers, mdf, wood, or aluminum?  Or does it simply not matter for a cylinder shape in the same way it does for a closed cabinet?  If I use CDT aluminum car speaker mounts, cnc'd specifically for my car, anything wrong with lining the inside of the cylinder with 1/8" closed cell foam?  thank you in advance.

invictus005 is completely on point in his post!

And, since I work for Paradigm, I’ll toot our own horn on this subject...

In regards to the Paradigm Personas:

The drivers are the only things we want to "sing" so we developed an enclosure that is completely inert. The enclosure is the launch pad for the drivers, holding them rigidly in place and dissipating the rear sound wave that they create, so that only the sound created by the drivers enters the listening room. To do this we build the enclosure out of seven sheets of wood composite material - High Density Fiberboard (HDF) with a Viscoelastic adhesive in between each sheet in a "Constrained Layer" configuration.

While the composite materials are being formed into the characteristic curved shape in a 5-ton press, a combination of heat and high frequency RF radiation is applied to begin curing and setting the adhesives. The curing process takes from 2 to 5 days. After that, the enclosure is carved to the proper
dimensions with a 5-axis CNC router. Lastly the FEA optimized marine plywood bracing is inserted and the end caps are installed.

From there, it goes to the paint shop to get its luxurious finish applied. This process involves 10 coats of primer and paint, with both hand finishing and new robot finishing methods utilized in between coats. From start to "finish", the cabinets take over 4 weeks to complete.

This is the ideal way to build a cabinet for an ultra-high performance loudspeaker. The only reason it’s not more widely used is the massive investment in tooling that is required. The result is a cabinet whose beautiful curves and fit and finish enhance its overall appeal and performance - much like a world class sports car.

So in short, having the resources we have at our 225,000 sq ft facility near Toronto, we can use anything we want to build cabinets, and this was only to explain how we build our best products. All the technology in drivers and crossovers don’t matter if you put them in a poor environment.

There is more I can share on our Personas, but I only wanted to explain what the subject pertained to.

Thanks to everyone who took, or takes, the time to read this, I appreciate it.

@veroman I don't know, having just ended a 25-year relationship with one resonance approach (expensively minimized), and invested in a completely different one (optimized/lossy, to my surprise), I find this a pretty interesting thread.  I don't know that one approach dominates, but the design choices are intrinsically fascinating.

@ebm. So true that high performers,or expensive items, are often maligned  by those who can’t afford them.  It’s funny really :)  many Timex wearers think Rolex is a total waste of money since it doesn’t keep time any better ;)  And for those types; often artwork is simply ink on paper - another waste of money ....

Hi @dave_b id love to listen to pair one day. You say he uses solid wood? 

Who gives a fig anyway...the best speakers I ever heard were a Bozak B-313b bookshelf speakers.  Great drivers and crossovers in a plywood veneered whatever box.  Didn’t care, they were unbelievably musical and dynamic and did justice to all kinds of music.  Sometimes execution means more than pseudo intellectual techno babble from wanna be designers.

Feed the speaker the impulse and rejoice or weep with the results.....
the cabinet stores and releases energy
how much, at what frequency and over what amount of time is critical
people do like all manner of distortion, coloration, etc....
the fact of the matter is there are few if any cost no object designs out there, so MDF in hands of capable designer is a very cost effective material.....

^says the guy with MDF speakers. Interesting.

birch plywood

Forest Signatures!  

Even MDF, if not fully covered, will change character in high humidity or dry conditions.  most companies cover their MDF with veneer and or paint to make sure this doesn't happen.  

They are using a ton of marketing terms.  I don't think there are any other companies out there that don't as they need to sell, lol.   It's all good. They make a nice speaker.  Some love them and some don't just like anything else.  

@dav, the only question I have of you is what model do you have that is made of all wood?  I can't find that on their site. Just MDF cabinets.  Maybe I misread but I thought you said that your speakers are made of wood???  Curious, that's all... thanks Pete

I use my ears!

"It helps to hear, literally, what is going on, by listening to the cabinet’s walls through a stethoscope, playing music and test tones. You find two things:

• Flexing of the cabinet walls allows low bass to come through. Out in your room, this adds in phase to the direct sounds coming from your woofer, making the overall presentation warmer, and adding bass ’ambience’ below 80 Hz. The bass is less tight, less defined, of course. Probably makes the hifi sound ’better’ at soft volumes.
  
  For low-bass flexing, braces help, granite helps, thick materials help, thin plywoods do not. Thin carbon fiber does not. Solid hardwood will split given time. Think here about maximizing panel ’stiffness’ or rigidity, not its ’strength’. Cement, concrete? Sure! FYI, paint the inside of wood cabinets with thinned-out wood glue-- as the surfaces of MDF and plywoods are porous, absorbing bass pressure whenever the woofer fires off.
  
  
• The other stethoscope discovery is that a cabinet lets voice range sounds, in the 200 to 300 Hz range, come right through. This makes for ’scratchy’ sounds in wood boxes and for ringing sounds in granite and metal. These vibrations do not come from the SPL inside the cabinet (unless there is a large, undamped (loud) standing wave inside). Those 200-300Hz vibrations come from the direct excitation of the cabinet material via the screws mounting ’that’ driver. When you loosen all its screws, all of a sudden, the walls go silent!
  
  One fix is to use rubber-mounted screws, but this makes bass impacts ’rubbery’. KEF and others tried this in the 80’s, giving it up after sales tanked from all that loose bass. The driver could be mounted to a regular inner cabinet with a vibration-isolated cabinet wrapped around it. Unfortunately, this leaves those inner-cabinet vibrations undamped, which get back to the driver, making its cone vibrate (= noise).
  
  When these tones get into the cabinet material via those screws, there is no way to damp them, and no way to brace against them, because they travel inside the cabinet material, not on the surface. If those screws cannot be rubber-isolated, the cabinet material needs to have ’high internal damping’, which is not a property of metal, cement, nor most woods. Cabinet thickness does not matter here, at least for making something to fit in a home.
  

For a home constructor, I recommend 3/4" Baltic birch plywood cabinets, or at least for its front panel, with braces inlaid 6-8 inches apart, center-to-center. But BB plywood is such a tough wood to work with and to make pretty! Two 1/2" BB layers glued up with Elmer’s Carpenter’s Glue made a front panel that was a bit more dead to those midrange tones getting into it from the screws, but not enough to justify the extra work. It made far more difference to put 1/4" wool felt on the front baffle to suck up the tweeter’s reflections before getting on with designing the tweeter’s crossover."

Roy Johnson
Green Mountain Audio


@royj, Sorry for almost missing your post. Every point you made/quoted seems to concur with what others have discovered through long arduous painstaking experiments. Thanks for that, Roy, I will print it off and keep it for reference. 

No (esp solid sealed) cabinet can do it all (great bass, mid and treble), but the heavily damped thin walled approach championed by the BBC (Harbeth, Spendor, etc) seems to do the least damage in the precious midrange.

So many of those speakers LS3/5, BC1s plus innumerable Spendor or Harbeth models are renowned for the purity of their midranges.

The use of stethoscopes and accelerometers sure has a funny way of saving us all a lot of time and energy!

Ok maybe dunking them in water or putting them in a kiln would cause the Totem’s to change their sonic character.  

@dave_b 

Ok Helomech the great...protector of things absolute!  Within the normal standards of cabinet design, Totem makes their speakers far less susceptible to various environmental conditions.  Their crossovers are special by virtue of quality and tolerances as well as being hardwired by hand.  

I'm the "protector of all things absolute," yet you use the word "impervious" to describe a speaker cabinet. Seems to me that shoe is on your foot Davey.

Dave, none of us have said that Totem doesn't make a nice speaker.  Many of you enjoy it's sound and feel it's a good value.  I auditioned them often as my local dealer has the line.  They weren't for me, but they were nice.  

Not sure why you jumped on helmomech like you did.  All he said was that you made a false claim.

BTW, I checked out most of their speakers on their site to see what hey are made of and they all seem to be MDF.  I haven't seen solid wood on any of them.  Which ones do you own?  The problem with solid wood, other than movement, is that each wood as a specific density and sounds totally different.  I have had many headphones.  My favorite material for cups so far has been Purple Heart and Boccote (my ZMF Ori's are the rare Boccote).  Sorry, not trying to get us off track on cabinet materials.

Ok Helomech the great...protector of things absolute!  Within the normal standards of cabinet design, Totem makes their speakers far less susceptible to various environmental conditions.  Their crossovers are special by virtue of quality and tolerances as well as being hardwired by hand.  

Vince at Totem makes cabinets impervious to environmental variations.

Gotta love these sort of claims. No such cabinet exists, nor will it ever exist. Just as no driver is absolutely perfect, neither is any cabinet or crossover. 

Vince at Totem makes cabinets impervious to environmental variations.  They are unique in the industry.  He also makes crossovers like few, if any others do.  

Daveb, sorry, I really misread your post, but those who know me, know that happens at times.  It's the MS to be honest, so sorry if my post came off wrong.  I agree, if you get a good feeling, that's what it's all about.  I could easily live with Harbeth as they are just musical.  Not the last word for detail or extension, but very nice speakers for anything.

I agree on natural wood and ply.  It really is a big deal too.  Especially when the cabinets aren't close to identical.  Worse than not matching your caps and resistors in the crossover. lol

The worst were the Wilson’s.  Magico’s were overly deadened to my ears.  Anyway, just saying I hear a dramatically improved sound with a well done wood speaker.  Harbeth uses this approach as well I believe.

The founders of Harbeth and Spendor did a lot of pioneering research into cabinet materials. Both companies now use cabinets made of MDF - and both are widely regarded as producing some of the most lifelike mids in the biz. 

The problem with solid woods and ply woods is their inconsistency, their susceptibility to warping and greater difficulty in machining. Even voidless birch ply will have slight variations between batches that can make it difficult to create a consistent sound. Musical instruments suffer this same problem. I've played brand new guitars of the same make, model that sounded very different from each other, even after professional setup. 

 

A resonant box adds distortion that is not coming from the real recording.  People like all sorts of colorations but don't imagine it's more realistic.

What I do is I sits my arse down and listens....if it I get a “Holy Crap” feeling, this sounds so freaking real and alive like live music, I’m satisfied.  Deadening anything too much sucks the life out of the music.  You can hypothesize all day long, but results are what matters.  I’ve owned the over damped, $20k plus speakers and found them soulless!

@georgehifi   your post about the surfboard hits the nail on the head. It's easy to think that stiffer/stronger/more solid must be better, yet all the strength in the world is no good if the cabinet becomes a soundboard at a critical frequency, especially in the midrange.

It's possible for loudspeaker cabinet materials to become almost transparent to the sounds coming from within the cabinet at certain frequencies again.

I think experiments have demonstrated that MDF untreated is more likely to act in this fashion.

And then there's the issue of a cabinet being too rigid and causing back pressure through the driver materials themselves.

Hugely complicated business is cabinet construction. Open Baffle gets around most of them but has its own issues.

Ctsooner, I wasn’t implying any particular speaker was “the best” silly.  I am saying that most of the speakers that I have owned tended to deliver a more natural sound when made of wood.  The worst were the Wilson’s.  Magico’s were overly deadened to my ears.  Anyway, just saying I hear a dramatically improved sound with a well done wood speaker.  Harbeth uses this approach as well I believe.  

Dave, have you heard all of them? I highly doubt it. Not sure what price ranges you are talking about, but I'd love to hear your conversation with Richard Vandersteen or Alon Wolf about this, lol.  Sorry, but you can't make that statement unless you have heard all of them.  I promise you my Vandy Quatrro's are plenty organic adn alive like real music in my room.  Plenty of speakers I've heard are outstanding and sound like live music and they are made of all different types of materials.

Totem are also nice speakers and I've enjoyed most of them at a local dealer as well as a dealer in NYC.  There is no best.  It's all design and implementation.

I’ve had the inert kind....sorry, but they do not sound organic and alive like real music.

@dave_b - speakers aren't the same.  Musical instruments are designed to resonate.  That's how they get their distinctive sounds.  Speakers, on the other hand, are designed not to resonate.  The less they resonate, the less of their own sound they have and the better they can reproduce the distinctive sounds of musical instruments.  

Wood...my Totem Cherry Forest Signatures Sound like a Stradivarius !  Fine musical instruments are made of wood.  Can you imagine a plywood, MDF or aluminum violin 🎻. Yikes!!!

Aluminum rings like a mutha!!! 

Everything resonates. Surely it's a question of where you put these resonances.

I believe it's far too easy to muffle the midrange with MDF or medite. Many specialist manufacturers purposely avoid the use of MDF for their cabinets, or at the least prefer some form of MDF composites.

Harbeth (along with Spendor?) is the exception, but then their entire cabinet construction techniques are also an exception. 

Actually aluminum is fairly inexpensive in the scheme of things.  It's how it's implemented and tooled that adds any expense.  Vandersteen had it right IMHO years ago when he went 'baffle less'.  It still works in todays market, but many don't love the look of the sock covering.  Teh Treo was basically the 2 in a full cabinet. form.  He was able to make it sound works better though as he had a better price range to work with and is able to use better drivers and components.  

The Thiel CS 7 had a concrete baffle.  There have been others.  Thiel stopped using concrete because it was too hard to ship without breaking.  I think the performance was great.  

I think it'd be an interesting challenge to build a really high performing box that was made out of cheap materials.  I'm sure it's possible, although maybe it wouldn't be practical for a manufacturer to mass produce.  MDF and concrete are cheap.  aluminum isn't all that expensive.  

Someone used concrete years ago for a small cabinet.  Forget who.  It may have a resonance that doesn't work. Can be measured of course.

If I had time I'd love to play around with this.  I'd try routing patterns in mdf and filling them with high strength concrete.  A bag of 6,500 psi concrete costs $8 and it's hard for me to believe it couldn't be used in combination with other materials to create a great box that didn't need to cost or weigh a ton.  

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

I haven’t read any of the answers, but something to ponder over which is material is going to flex the least, and becoming a sound board at certain frequencies in a speaker
In my younger years as a comp surfer, I tried all three in the centre stringer of my comp surfboards, this could be a good indication.
Flex and rebound is a good thing in a surfboard as it gives feel through a turn and rebound coming out of a turn (bit of a kick of speed) bit like snow skii’s when you get a good rhythm going in slalom racing

All three stringers (mdf wood ply) on surfboards being the same thickness, the one with the most initial flex is MDF as it has no grain it’s flexable but it doesn’t rebound (snap back) as good as, single ply of wood, single ply of wood doesn’t have the initial flex of the MDF though.

The stiffest with not much flex or rebound is the 3 ply of wood as all 3 plys are grained if different directions to each other and glued together.

So to me for speakers say thick 15 ply with all grains running in different directions will be stiffer, so not to flex much and become a sound board certain frequencies. Sure they will still have resonances but they should be well down and maybe easy to tune out with strategically placed bracing.

These guys think the same
https://www.google.com.au/search?q=Shahinian+speaker+with+plywood&sa=X&tbm=isch&tbo=u&am...

Cheers George

i should probably disclose i use a bunch of Vandersteen and HRS products......