[pianotech] Yamaha C2 voicing problem

[Ed Foote]

Do these hammers have the shoulders well loosened up, or are they hard 
rocks with a little softening around the top?

Ed Foote RPT
http://www.piano-tuners.org/edfoote/well_tempered_piano.html

-----Original Message-----
From: David Love <davidlovepianos at comcast.net>
To: pianotech <pianotech at ptg.org>
Sent: Tue, Oct 30, 2012 6:56 pm
Subject: Re: [pianotech] Yamaha C2 voicing problem



Btw, a slower sequence would be better. 
 

David Love
www.davidlovepianos.com

 

 From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On 
Behalf Of David Love
Sent: Tuesday, October 30, 2012 4:49 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Yamaha C2 voicing problem

 
The worst notes to me are the 3rd note and the 5th note (going up).  
The top two notes  (7 and 8) sound ok. 
 
David Love
www.davidlovepianos.com
 

 From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On 
Behalf Of Jim Moy
Sent: Tuesday, October 30, 2012 3:17 PM
To: Pianotech List
Subject: [pianotech] Yamaha C2 voicing problem

 
The patient is a 1995 Yamaha C2, and the tone in a particular area of
the bass has been bothering a customer.

Here's an mp3 file I recorded with my iPhone. It's a diatonic octave
being played from around C2.

https://dl.dropbox.com/u/147189/yamaha-c2.mp3

The sound he doesn't like is most evident on the seventh and eighth
notes played on the recording, and the same two notes on the way back
down the scale. Can anyone identify the source of the sound, and suggest
a remedy? The sound reminds me of a "normal" bass note being played
simultaneously with a large drop of water dripping into my tub when the
bathroom is quiet. Maybe a little "woodier" than that. And shortened up
in duration. The onomatopoeia might be "poink, poink" for that portion
of the sound. Depending on what the customer is playing and where I am
standing, the sound may be more or less obvious. Neither of us noticed
the sound on the pre-purchase inspection. Since the move, he has had a
Dampp-Chaser installed.

I've isolated it from the dampers, damper levers, and damper stop rail.
I've tightened the screws on the hammer shank flanges and checked the
hammer glue joints are sound. Hammer mating is good. I forgot to check
traveling. I can make the sound more prominent by shifting the action
"out" of the cavity about a quarter to a half inch, for a slightly
shorter speaking length. Seems to be happening only on the bichords.
I've done some delicate single-needle voicing just enough to alter the
tone but notice it wasn't diminishing the objectionable sound. I'm
hesitant to just jump in and experiment (juice up the hammer?) because
it's already got a nice, even, "Yamaha" sound.

But are these bass notes just "the way it sounds?"

Jim