interesting wood article

[gordon stelter]

Heard a glass violin on the news last night. $50,000.
Sounded like garbage.
     I do believe that anyone with common perceptivity
realizes that piano soundboards work BOTH as waving
diaphragms, AND resonant bodies. And this, in
combination with the resonant/transmittant aspects of
the case, creates the distinctions in tone betwixt one
piano and the next.
     We can "fiddle" around with this factor or that
in attempts to bend the tone as we desire, but I do
not believe that such a  complex system will EVER lend
itself to complete analysis by computaional method.
     And, frankly: "So what?"
     Thungeeeeeeeeeeeeee
     ( Mason bass )
     
--- Richard Brekne <Richard.Brekne@grieg.uib.no>
wrote:
> 
> 
> Farrell wrote:
> 
> > At the risk of  asking a question that has been
> asked a zillion times
> > before...... Is there perhaps a fundamental
> difference in the way a
> > piano soundboard vibrates compared to whatever on
> a violin vibrates
> > from string movement to produce their respective
> sounds?
> 
> Since the point goes to the general acoustic
> properties of wood... I'm
> not sure whatever differences in construction
> between various types of
> instruments is at all relevant.
> 
> Is the piano soundboard moving more like a speaker
> cone (I realize most
> soundboards are pretty far from that ideal) compared
> to the vibrating
> front of the violin? I ask that because if piano
> soundboard movement is
> closer to the speaker cone, we are strictly looking
> at a vibrating
> diaphragm, and the ability of the soundboard
> material to "transmit
> sound" is a mute point (pun intended). To the best
> of my knowledge,
> speaker cones do not "transmit sound", but rather
> move as a single unit
> at whatever frequency(s) is required to produce
> intended sound - paper
> cones work well, but carbon-fiber or a number of
> other exotic materials
> with greater stiffness-to-weight ratios than paper
> work better - but not
> because the exotic cone material "transmits sound"
> any better, but
> rather because the material moves more efficiently
> as it is driven by
> the speaker voice coil - or in the case of the
> piano, the string.
> 
> Well.. all I can say is that number one.. I've never
> bought into the
> idea that the soundboard functions strictly as a
> speakercone does, and
> secondly... if wood can transmit sound at all...
> then speaker cone or
> not... you cant overlook the...er.. transmission as
> it were..  Besides
> ... if the pianosoundboard could so easily be
> defined and modeled...
> then we could have replaced the material with
> something else and
> achieved exactly the same sound years ago.
>  So my question is - is the speaker cone analogy
> more closely related to
> the case with the piano soundboard and less so with
> the violin? No
> relationship?
> 
> I personally would think the piano soundboard
> functions far less like a
> speakercone then some would have it, and the violin
> functions more like
> a speaker cone then purists in that camp would feel
> comfortable
> admiting. Again, if fear this has been asked before
> - and if I've read
> info on it, I guess that means I just haven't
> thoroughly understood it.
> 
> Its been done over a zillion times, and if people
> with all kinds of
> fancy initials behind their names continue to
> dissagree on the subject,
> I suspect there is good reason for that
> dissagreement-...., and I
> certainly would expect to find continued
> disagreement in forums like
> this one. And here's a question that may not have
> been asked before (and
> maybe for good reason): "As wood gets older,.....and
> displays lower EMC
> levels." Does it? Or does it simply become slightly
> less dense from
> losing volatile components, and then simply carries
> less water in it at
> the same EMC?
> 
> Well... I dont know... I'm just putting out
> information as I run into
> it. This latest came from largely from teh Tampere
> University of
> Technology in Helsinki, tho there are some other
> resources on the nett
> where you can find similiar information. The fellow
> behind this
> particular study was one Pertti Nieminen, Docent,
> Ph.D.  He's the guy
> (grin... amoung others) you want to ask. Tho I will
> look through and see
> if Hoadly has anything to say on the matter.
> 
> I just think its all interesting perspectives to
> read what different
> researchers around the world come up with. I wish I
> understood half of
> it as much as I should, and all of it more then I
> do... if you get my
> meaning.
> 
> Cheers
> 
> RicB Terry Farrell ---
> Richard Brekne
> RPT, N.P.T.F.
> UiB, Bergen, Norway
> mailto:rbrekne@broadpark.no
> http://home.broadpark.no/~rbrekne/ricmain.html
> http://www.hf.uib.no/grieg/personer/cv_RB.html
> 
> 


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