My Unscientific But Probably Valid Reluctance To Use MDF

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I'm not an engineer and don't try to play one on Usenet, but I avoid
MDF because of some common sense reasons.

It is hygroscopic (yeah, I mistyped the word last time) which means it
picks up water. If it gets good and soaked you might as well build a
big bonfire and burn it, standing well upwind.

It is nonresonant, but its absorption spectra is such that it tends to
make speakers using it sound not just neutral but "actively dull". We
call that "crapping up the sound", in unscientific terms.

It's less rugged than good plywoods and is unrepairable. I have seen
many guitar cabs that if plywood could be repaired by judicious
clamping and epoxy without destroying the Tolex, but in MDF must be
stripped of drivers and burned. That's the only way to get rid of it.

Composites are certainly OK for cabs if they are engineered for the
purpose, but they are probably beyond the home constructor, except for
machinable prefabricated materials like Corian. MDF is a composite too,
just IMO an unsuitable one.

I'm sure this will drive Arny to apoplexy, but that's the deal as I
see it.

[Howard Ferstler]

wrote:
>
> I'm not an engineer and don't try to play one on Usenet, but I avoid
> MDF because of some common sense reasons.
>
> It is hygroscopic (yeah, I mistyped the word last time) which means it
> picks up water. If it gets good and soaked you might as well build a
> big bonfire and burn it, standing well upwind.

Well, if you are stupid enough to leave your speaker out in
the rain this might be a problem. No doubt the rain would
not be too good for the drivers, either.

> It is nonresonant, but its absorption spectra is such that it tends to
> make speakers using it sound not just neutral but "actively dull".

This is absolute baloney. One wants the cabinet to sound
dull. It is the drivers we want to hear. The "duller" the
cabinet is, the better.

> We
> call that "crapping up the sound", in unscientific terms.

In nitwit terms, too.

> It's less rugged than good plywoods and is unrepairable.

Meaning that it is a good idea to leave your speakers
sitting where they are supposed to be and not play catch
with them.

Howard Ferstler

[ScottW]

> wrote in message
oups.com...
> I'm not an engineer and don't try to play one on Usenet, but I avoid
> MDF because of some common sense reasons.
>
> It is hygroscopic (yeah, I mistyped the word last time) which means it
> picks up water. If it gets good and soaked you might as well build a
> big bonfire and burn it, standing well upwind.

All wood products are to varying degrees... plywood too, even outdoor
grades.

You planning on soaking your speakers? How will your drivers and crossovers
stand up to that?
>
> It is nonresonant, but its absorption spectra is such that it tends to
> make speakers using it sound not just neutral but "actively dull". We
> call that "crapping up the sound", in unscientific terms.

Now you're making stuff up. I suppose the absorption spectra of a
comfortable listening chair will crap up the sound as well. I think you
should be listening while seated on a spike for optimum "uncrapped" sound.
>
> It's less rugged than good plywoods and is unrepairable.

Plywood will inevitably delaminate and then buzz which will really crap up
the sound.

> I have seen
> many guitar cabs that if plywood could be repaired by judicious
> clamping and epoxy without destroying the Tolex, but in MDF must be
> stripped of drivers and burned. That's the only way to get rid of it.

You must have inhaled a bit too much formaldehyde from your MDF torching
parties.

What does guitar speakers cabinets have to do with Hi-fi speaker cabinets?

ScottW