Would you say that that veneered birch plywood is a better material to prevent vibration than veneered MDF for audio furniture?
The main vibrations in my room come from bass traveling through the air (not the floor) that causes the furniture to vibrate.
I read that plywood is stronger and stiffer than MDF but perhaps MDF more damping.
Note: it’s not a rack but a piece of furniture under the tv.
When I built my rack and before that some years of speaker building, I found veneered MDF best.
MDF is inert, plus it’s not affected by normal domestic environmental conditions or change shape over time.
Natural wood will always change depending on humidity and temperature, wood ply does the same to some extent, multi layered and marine ply less so.
Yeah I meant multi layered birch plywood
MDF is truly horrible stuff and I avoid it. Legislation has forced manufacturers to reduce formaldehyde content and to control risks to workers during manufacture and cutting, but it’s still quite nasty. So for that reason I would use plywood, or better still, solid timber.
On the other hand, for performance, MDF is probably the better choice, although in a regular piece of furniture I suspect that is of little relevance.
I prefer good quality structural plywood over MDF.
Tough question. Several high end racks used solid ash. So neither plywood or MDF.
And yet a few high end speakers (like in the $300K category) use plywood cabinets rather than MDF.
I guess the choice really comes down to how well you understand the material and know what you’re doing.
I think the implementation is as important, and possibly more important, than the actual material. I believe Fraim uses veneered MDF shelves, and some high end racks use plywood. So probably both materials have merit for audio use. Which will perform better in your specific application is anybody’s guess. Ideally you would make two racks from the different materials and compare the results. This is tedious and expensive so therefore impractical. Personally I would just use whatever is easiest to work with and finish well so that it looks good.
MDF has a more consistent density and has superior damping properties.
Baltic plywood furniture has significantly more strength, lighter, and will last for decades.
Personal choice, no MDF anywhere.
Yes, we have an MDF free house, which is good. I always thought loudspeakers would have to be an exception, but by a happy coincidence my preferred Shahinians are made from birch plywood.
There’s a lot of quality difference between MDF. It’s certainly possible to buy the better mdf and use that instead of the standard diy stuff.
Yes, but for furniture/structure, plywood over MDF every time.
Lots of useful info! A lot more useful than following ChatGPT’s advice blindly.
I agree. When I made up some platforms for my s/h Arivas, I sought advice on the forum and got pushback for going for solid wood in preference to MDF. I chose to ignore those comments for similar reasons to yours and, years later, do not regret it for a moment.
You can’t get a definitive answer to which is best for vibration control in hif furniture by asking. You need to know what and how you’re going to achieve in your design. Birch ply will be far stiffer and the resonance higher. This can be good or bad depending on how it’s used. As a constructive material, mdf is a pain to use and needs careful constructive techniques or it will be rubbish.
Shahinan use the finest birch ply in the cabinets, but they use that as part of the design to produce the sound, like a violin.
Naim Fraim is a high frequency stand, not a dull vibration damping one.
The above is based on you making it. If you’re looking at buying, forget the theory and just go and listen.
My view as a chippy of over 30years
MDF is the material of choice for the majority of speaker manufacturers for once reason only and that is that it is less expensive and gives them better margins. MDF is only stable if it is completely sealed otherwise it’s probably the least stable material to use as it quickly absorbs moisture and becomes unstable significantly quicker than a good quality plywood.
High quality birch plywood, Marine grade mahogany/Oakum ply. All better sheet materials.
Also consider Bamboo ply for furniture as when cut and sanded and given a light oiled and wax finish looks attractive and does not require secondary labour intensive procedures prep for and paint or veneer finishes.
You are right about the stability of mdf in damp conditions, of course, but in a domestic setting, I can’t imagine it being a significant problem once it’s veneered and sealed.
I won’t pretend to understand the science behind it, but my understanding is that mdf is preferred for its acoustic properties in some speaker designs compared to other materials. Some pretty expensive cabinets have been made from veneered mdf: you’d think for products that retail for tens of thousands of pounds a designer would be free to use other materials if they thought it improved performance. It might be interesting to get the opinion of a speaker designer on this, although I’m not sure if there are any still working at Naim.
Having used low grade MDF, high grade MDF, HDF, and also BB ply and Veneer ply…the Baltic Birch Ply and Veneer Ply sounded better by a fair bit. A single application of constrained layer damping material (e.g. ‘dynamat’) really changes the game, IME. As others have stated the formaldehyde in MDF isn’t very appealing, and it’s hydroscopic in every varietal I’ve seen.
Purely based on sound quality, it’s a hands-down victory for the wood ply options. Which are, as many others have stated, always more expensive by a real margin. E.g. an 80L high grade 20mm MDF cab with real veneer on the outside, finished, could cost $600-$800/pair in raw cost (assuming far East production like Indonesia). One can stack cost quickly by specifying better finishing processes.
A Baltic Birch ply cab of the exact same dimensions would run you close to double that ($1100-$1500). Add literally any finished veneer on the outside and you’re talking adding another 20-40%. Just for raw cabs. Make them domestically in the West, and you’re nearly doubling that again.
Thanks for your detailed response. Could you elaborate on the above as I am not very familiar with it.
Happy to. MDF and HDF have higher internal damping than wood ply. Which is congruent with how they are made; MDF/HDF are made from a fine wood pulp slurry, impregnated with resin/epoxy…whereas wood ply is actually thin slices of actual wood that is glued together then pressed (usually under heat) and then cured.
I’m over-simplifying, but you get the idea.
So, to add some damping effect, the mastic constrained layer (e.g. dynamat) is applied to the interior of the cabinet and it converts most of the vibrational energy into heat, whilst having a secondary effect of converting high-Q vibrational events (read: resonant peaks) into low(er)-Q events…spread over a much bigger frequency band, at a much lower peak amplitude. Not unlike drum gels if you’ve ever used those on percussion instruments.
An additional benefit of mastic constrained layer damping is that one can apply as much as they need, exactly where they need it.
BBC thin-wall type construction nearly exclusively uses wood plies. Put simply, because they sound better in that use case…and not by a small margin.
Interesting, ChatGPT also mentioned an idea to me which I think is similar to what you imply. It suggested putting butyl at the bottom of the inner cabinet to get rid of vibrations.