Soundboard Installation & MC

[Robin Hufford]

Del,
     What do you suggest the torsion resonator does, in fact, do?     I can
understand M&H continuing to use the device as it seems an integral part of the
concept of a  Mason & Hamlin, and it would, indeed, be foolhardy to forsake it,
particularly when it is hard enough already to sell enough of the instruments,
given the realities of the market of today.   However, I am not able to see much
it can be technically useful for in reality, and I agree, as far as I can see,
that it is not significant in forming or maintaining crown.
     As to its ability to prevent spreading of the rim, surely the plate is at
least equally efficacious, if not more so in this regard than the resonator.  In
highly traumatized pianos that have suffered substantial impacts, one can easily
see the effects of  the structural integrity of the inner rim/plate assembly,
operating as a unit, as an opening  can frequently be found developing between
the laminations that comprise the inner rim and those of the outer rim.  Many
years ago I repaired a M&H A that have been pushed off a stage; the partial
detachment  of the inner rim from the outer was evident through the case.
     Some years later I evaluated a Yamaha C7 for a dealer that had been hit by
a car which had passed through the outside wall of a house.  The car had been
substantially decelerated by  passage through the wall and it basically came to
a stop just as it contacted the piano upon it which it inflicted little shock
but substantial torsion.   The polyester finish in the piano was unbroken
although slightly marred and the insurance adjuster had claimed the damage to be
merely cosmetic.  In fact the piano had been heavily squeezed between the car
and a large amount of other furniture; one could see in the finish slight traces
of a line where it was evident the two parts of the rim had undergone relative
motion; the case had been squeezed enough that the outer rim had popped loose
from the inner assembly which illustrates the strength of the inner assembly
and  a beam had broken loose near the tail.  However, in no place was the
polyester even cracked.  The piano played, and sounded just fine, but it was a
total loss as it had completely lost any predictability of use.  On old pianos,
again, one frequently finds the rim to be somewhat delaminated, a subject
addressed lately here, and this is generally between the inner and outer rim, at
least functionally.  These things lead me to  think the inner rim,  when
strengthened by the plate attached to it, is already more than sufficiently
strong and will, generally, adequately  restrain the entire case from
substantial spreading and, I would think, certainly  is at least as effective as
the torsion resonator in this regard.
     At the time of its development however, the stability associated with a
continuous rim was, as you know, a relatively recent development and I think a
case can be made that there were many older pianos then in existence which
indeed had  unstable rims, a fact which facilitated the commercial utility of
the concept of a remedy, hence the torsion resonator and its development.  Once
in use, it seems to me it would be a great sales risk to forego such an arcane,
obvious emblem of technical superiority, whether actually effective or not and
so it continues.  I, for one, cannot place much stock in a sales pitch placed on
line by a company whose purpose in doing so, naturally, is not merely
informative.
Regards, Robin Hufford


Delwin D Fandrich wrote:

> ----- Original Message -----
> From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
> To: <pianotech@ptg.org>
> Sent: April 27, 2002 2:42 PM
> Subject: Re: Soundboard Installation & MC
>
> > >
> > > Just to keep my position clear, I've not said the thing is useless. I've
> > > said only that it is not effective in forming or maintaining soundboard
> > > crown. Quite a different thing entirely.
> >
> > Ok...fair enough... but to be sure.... what purpose(s) does this system
> serve
> > that then makes it worth the effort and cost to install ?
>
> Obviously it's a good marketing tool. Beyond that, since I have no idea what
> it costs to install I can't really say whether it's worth the effort or not.
>
> As to what it does do -- well, I've written about this device two or three
> times in the past.
>
> Del