As a first step, I like to check mating: with pedal down, press the hammer very lightly on the strings, using a finger on the shank (finger resting on the hammer rail, for control). Pluck the strings and see if one is more open than the other. File the hammer on the side that is more muted until both sound equally muted. Whether or not this is the cause of the problem, mating will give the note better focus, less "junk" in the sound, a more steady rise in tone color when playing with added force.
If I decide I do want to voice the hammer, I would start by playing the note with each string muted in turn, to see if one is more of a problem than the other. I would probably use a single needle, inserted very close to the center of the crown, angled into the hammer away from the top of the core. I am trying to maintain a triangle of untouched felt above the top of the core molding, something like 60º, so the angle of the insertion is in reference to that. I generally use single needle in one of those fairly cheap voicing tools that can pivot for this kind of thing. You can usually angle it so as to do top and bottom of the hammer.
Start with one insertion on either side of the middle of one string groove, listen. Possibly 2 - 3 insertions on either side of both string grooves would be about as much as I would do. 5 - 7 mm deep (deeper as you move out from the middle). It would partly depend on what I felt in the hammer felt: is it quite hard, resistant to the insertion? Is the problem mostly just attack sound? If this is so, some very shallow needling (2 - 3 mm) right in the grooves might help.
Whatever you are doing, play the notes around it to compare.
Another thing to consider is mismatched strings (not likely to lead to this particular complaint, but maybe), and the possibility that there is a longitudinal mode issue. If the latter, it will be a sound in an individual string, and it will go away as you tune it up or down by up to 50¢. I don't think so on a U3, but it is a good thing to bear in mind for similar problems with other pianos.
-------------------------------------------
Fred Sturm
University of New Mexico
http://fredsturm.net "When I smell a flower, I don't think about how it was cultivated. I like to listen to music the same way." -Federico Mompou
-------------------------------------------
Original Message:
Sent: 09-23-2014 20:30
From: Michael Crosby
Subject: voicing out high partials?
I have a customer that recently purchased a Yamaha U3. The piano is in original but good condition. Her biggest complaint is when she plays D2 the
high partial that sounds is driving her crazy. I can hear it to some extent on surrounding notes but this one is the one she hears the most. She is a enthusiastic but beginning level player. Any ideas on how to reduce this overtone she is hearing. I told her that I would check with the voicing Yodas and see what I could learn thanks.
Michael Crosby
Kennesaw GA
770-309-1585
-------------------------------------------