How good / bad is MDF for use in speaker cabinets?

[Steven Holt]

if the sony sscs5's are made out of MDF then by god it's good enough for me.....

 

[Tangband]

So in effect what you are saying is that you would like speakers to be even more expensive without audible benefits. I'm sure Magico and the likes are thrilled to hear that, but I'm not sure I understand why.

EDIT: I understand it for products that are expensive (and make expensive design choices) just for the sake of being able to sell in the luxury segment, but that's not what the 8381 is.

Using different materials , as in 8381 can probably be beneficial.

 

[tinnitus]

Concrete is the choice of material

 

[pablolie]

So you're saying MDF is not compromised SQ wise compared to any other material ?

There are different grades of MDF. It can be super solid. Also a simple matter of the thickness of the material.

And if is measures great, why worry about whether it's MDF or cast in platinum?

 

[kemmler3D]

But would it actually be crazy heavy for the same stiffness? I suspect not. For example I’d expect a 3/4” panel of MDF to have similar stiffness to a 1/4” thick dense concrete panel?

I don’t know…but the advantage of “any shape” is huge IMO.

I very loosely ran the numbers on this and I think you can use concrete at about 1/4 the thickness of MDF and come away with similar stiffness. This gets you a similar weight for the object as well, since the density is around 4x.

The "any shape" advantage is also huge IMO, but manufacturing concrete items is much slower than MDF, so you won't see it in mass production very often. And creating forms that aren't just rectangular still requires you to build said form from something else, and in the DIY world that often just ends up being woodworking again.

 

[Mnyb]

More concrete speakers from Rauna ,they have developed their own formula for this concrete as the problems are numerous, so it’s not exactly the same stuff as in you house , gues you experiment with aggregate and additives, with such a small thing as a speaker.

 

[Ken Tajalli]

Concrete can take any shape and is stiff.

Why not concrete?

They did make some!
I do recall one speaker with cavity walled enclosure, that one would fill with water or sand.
Didn't catch on.

 

[pablolie]

I'd say that it is myopic to just look at the cabinet material to try establish if something is a better or worse speaker. Clearly the material is a design choice as well as a reflection of the price target you shoot for - as are all the other choices.... inhouse or OEM woofers or tweeters... quality of the crossovers... etc etc

 

[sigbergaudio]

I'm sure there are many materials that could work when done right, but it's solving something that isn't really a problem to begin with.

 

[Pearljam5000]

How can you tell if it's a quality MDF or some IKEA stuff ?

 

[IPunchCholla]

There are multilayer composites made with MDF, too. David Smith era Snells used two layers of MDF with a damping later in between. Earl Geddes used that approach on Gedlee speakers as well. The newer damped bracing designs from e.g. KEF seem to be a more efficient means of doing the same thing.

Personally I don’t much care for MDF, though I won’t throw my Revel Gem2’s out for being made of the stuff, either. The corners get damaged easily and when I thought I could build cabinets I hated working with it. All of the wood speaker cabinets I’ve commissioned in the last decade or so have been Baltic Birch or a domestic hardwood ply called Appleply. Prices have risen since then so I don’t know what I would spec if I were to commission something now.

There are also other materials to consider. One is HDPE board (Starboard). I’ve had a couple subwoofer cabinets built from 1/2 Starboard (double thickness baffles) and they’re great. Geddes switched over from constrained MDF to a polyurethane board called Renshape. I’m not sure anyone currently uses that.

How does HDPE compare to MDF in performance? I just made some speakers out of 19mm MDF (38mm baffle). I got curious about HDPE but it looks like the price is 5 to 10 times the equivalent in MDF.

 

[IPunchCholla]

But would it actually be crazy heavy for the same stiffness? I suspect not. For example I’d expect a 3/4” panel of MDF to have similar stiffness to a 1/4” thick dense concrete panel?

I don’t know…but the advantage of “any shape” is huge IMO.

Concrete has ringing issues. So bracing and damping can get complicated. It also isn’t very strong in certain directions without reinforcement (hence rebar), which introduces a lot of complexity. Like you say the Ada vantage is shape, but casting can become very complicated, requiring bladders etc. and a lot of labor to both maIndian the casts and finish the concrete.

 

[fpitas]

How can you tell if it's a quality MDF or some IKEA stuff ?

Just wait until Genelec offers the MDF knock-down economy version of the 8381A.

 

[IPunchCholla]

How can you tell if it's a quality MDF or some IKEA stuff ?

What makes you think IKEA stuff isn’t quality MDF?

 

[pablolie]

What makes you think IKEA stuff isn’t quality MDF?

IKEA has different qualities of MDF, too. MDF can be made extremely solid. I am waiting for forged carbon to make it into speakers. :-D

 

[IPunchCholla]

In the MTB world, in the last 15ish years, we have seen frames go from steel, to aluminum, to carbon, back to aluminum in terms of higher end ”Halo” bikes. Each of these shifts have been touted as revolutionary. Really, it just depends on what you target bike is, what scale production you are talking about, how much you think you can charge, what your design goal for the frame is. No material is superior to the other. Each has its advantages and disadvantages (steel is relatively abundant and cheap, and can be more cheaply welded than aluminum. Aluminum is stiffer, lighter, stronger than steel, but more expensive to weld. Carbon is easier to make exotic shapes and to also target stiffness and compliance and can be stronger than steel in some ways, but is more expensive to make because of time and labor involved in the process).

So really, choosing a material should be based on your design goals. For most speaker shapes (variation on a rectangular box), MDF provides a very compelling mix of availability, cost, good acoustic properties, easy manufacture. If you are doing exotic shapes, need lighter weight, etc. other materials may be better.

 

[Pearljam5000]

Just wait until Genelec offers the MDF knock-down economy version of the 8381A.

But it's already MDF

 

[Sokel]

The comparison between alu and wood seen in my previous post is done with Panzerholz.

You can see it's data sheet here (last in page):

Delignit

www.delignit.de

Edit:I searched a little and I saw that they even make phono cartridges with that

 

[Pearljam5000]

The comparison between alu and wood seen in my previous post is done with Panzerholz.

You can see it's data sheet here (last in page):

Delignit

www.delignit.de

Edit:I searched a little and I saw that they even make phono cartridges with that

This company is known for using it

 

[Ken Tajalli]

I'd say that it is myopic to just look at the cabinet material to try establish if something is a better or worse speaker. Clearly the material is a design choice as well as a reflection of the price target you shoot for - as are all the other choices.... inhouse or OEM woofers or tweeters... quality of the crossovers... etc etc

Of course!
The cabinet, enclosure, is but one component of the whole speaker.
Did anybody claim that the enclosure, and the material used, dictates the final sound?
Fun fact: original BBC LS3 5A design, specifically uses a thin 12mm plywood for the box. Because it would warp in and out, and in doing that, it dampened a certain resonance! So I had read.