Hammer Types

[David Love]

In this case, with the 175, we were working with one soundboard and scale
design--basically a lightish s/b and low tension scale.  The results that
were less pleasing were with the harder hammers and can best be described by
the peak of the attack envelope being too far above the ensuing level of
sustain.  IN the bass, the harder hammer produced a weaker fundamental with
poorer pitch recognition and a less round tone.  Overall, the attack was too
percussive and it created the perception of poorer sustain because of that
difference.  The Wurzen hammers had a similar effect but to a somewhat
lesser degree than the Abels.  In all fairness, a couple of the listeners
(there were probably 8 - 10 people who listened to the results) did prefer
the Wurzen hammer (no one preferred the Abels) but only after fairly heavy
voicing.  The level was still somewhat above the Ronsen Bacon felt hammers.
While it may be possible to voice any of those hammers down to the level
where they needed to be to match the s/b string scale, one point of the
exercise was to try and determine which hammer in its most raw form was the
best fit for this piano.  Also, there is a difference between taking a
harder hammer and voicing it down and having a hammer that starts at that
level to begin with.  Perhaps it has to do with the relationship between
density, flexibility, resilience and tension.  A heavily needled hammer has
different balance of those characteristics than one that is that level of
softness to begin with.  

Another of my goals was to work with the hammers only in so far as they
could reasonably be dealt with in a production setting.  So while I did
voice the Abel and Ronsen Wurzen (and eventually voiced them quite heavily),
I tried to keep my initial treatment to a point that one could reasonably
expect the factory voicer to do on each piano before leaving the factory.
The 190, btw, with a slightly higher tension scale seemed more tolerant of a
harder hammer even though the Bacon felt hammer was still plenty to drive
it.  

I think you can draw the conclusion that generally speaking the lower the
tension and lighter (or less stiff) the board the softer the hammer that is
required.  One problem is that not all scales match the boards they are on.
You see low tension scales on a relatively stiff boards, high tension scales
on loose boards and all kinds of combinations both by design and because of
changes in the s/b assembly over time.  In those cases it's not clear to me
what the best hammer will be as soundboard response will vary and in
different ways.  In those cases, sampling will have a better chance of
steering you in the right direction.  

David Love
davidlovepianos at comcast.net
www.davidlovepianos.com 


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Cy Shuster
Sent: Friday, October 06, 2006 5:58 AM
To: Pianotech List
Subject: Re: Hammer Types

David,
 
In your side-by-side hammer tests, what did the negative results sound like?
 
Hard hammer + flexible s/b = overdriven sound, distorting?
 
Soft hammer + stiff s/b = no power, no sustain?
 
Can it be reduced to the ubiquitous graph with four quadrants?
 
--Cy--