[pianotech] Sustain

[David Love]

My experience tends to agree with this.  The overall length of the sustain
is not actually increased, but the differential in amplitude between the
attack phase and the beginning of the sustain phase is reduced and the piano
sounds less percussive with the perception of greater sustain or a greater
singing quality.  Introducing greater flexibility in the shoulder (and
sometimes the crown) is necessary to reduce the amplitude at attack.  The
older and/or less stiff the soundboard the more flexibility is required of
the hammer to lessen that percussive quality.  Interestingly, were you able
to compare the soundboard/hammer interface in the original condition where a
stiffer soundboard was a better match for the relatively harder hammer you
would probably not find much greater amplitude in the attack phase since the
greater stiffness of the soundboard would provide the control and the now
too hard hammer would be less consequential.  As the board gets weaker that
control must necessarily pass to the hammer.  It's the argument for
replacing old hammers on and old soundboard with a softer version than was
on there originally--or be prepared for some serious needle work.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: Tuesday, December 30, 2008 3:24 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Sustain

At 15:58 -0600 30/12/08, Ron Nossaman wrote:

>...The tonal envelope in the "short sustain" section had a sharp 
>short attack spike, with the dwell and decay considerably quieter. 
>The impression, even though the total duration was similar, was that 
>the sustain was short. What worked best on this piano was side 
>needling high shoulders. I had him listen while I worked a hammer 
>and he could hear the attack peak lessen, and extend further into 
>the tonal envelope, blend more smoothly with the dwell and decay. 
>The impression was a longer sustain, but it was just a 
>redistribution of the power curve.

I had a very similar experience this year with a very old but quite 
nicely rebuilt big Blüthner when I was called in by some London 
colleagues to tone and regulate it in order to satisfy a "very fussy" 
"prima donna" type who was due to give a recital on it.  My 
preconceptions and my initial impressions of the piano led me to 
think that I would not end up satisfying the man and saving my 
colleagues' reputation and pocket.  I demonstrated to the man what I 
saw as the problem, namely a short attack followed by an uneven and 
too rapid decay and he was able to hear what I was showing him. 
Politics did not allow me to tell him I doubted if I could make much 
improvement.

By the end of the job, which took about 16 hours including a lot of 
regulation work, he was delighted with the piano and I myself thought 
I wouldn't mind having it at home.  Exactly how it works I'm not 
sure, but I accounted for it rather as you have described.  Somehow 
the attack, although it was not terribly metallic, was stealing from 
the dwell and sustain.  Contrary to my initial fears, there was no 
significant energy being lost in the resonant structure, and once the 
tonal envelope was rectified the soundboard sang like a goodun in 
spite of its 120 years. The hammers were plain off-the-shelf Abels 
and not what I would have used myself, but the result was fine.

I must say that I find that sort of job the most rewarding of all, 
not least because one has first to listen very carefully to the 
client and translate his or her artistic ramblings into usable data 
for the progress of the work.  In this case the pianist was indeed 
fussy and full of artistic soul but he knew something was wrong and 
as the work progressed I found out exactly how to satisfy him and 
myself into the bargain.

JD