Short sustained sound of Boston GP 193

[JamieD]

I regularly tune a Boston GP 193. I also did a full day service on it, including hammer shaping, mating and voicing. The action works very well.
The main problem is the overall short sustain of the grand. A recording of a concert was done a week ago and I could listen to it. There are no tuning problems or so, it simply sounds like a fortepiano. The sound is somehow smothered.
Sitting in front of the grand this problem is not so obvious. Maybe the room is a little too big for the Boston, but I think that it not the problem.
I rechecked the bedding of the key frame, it seems to be ok. From d5- g6 I had to put in some felts to mute the instrusive ringing from the NSL on about 8 notes, which rubs a little power of course but is surely not the culprit of the poor sounding instrument.
I tried to add some resilience to the shaped hammers by doing deep shoulder needling, nothing helps to open up the nasal, thin tone. It is like there is no "body" in the tone. Especially in the bass and the notes up from d5 to c7.
I also tried to change the position of the action back and forth. It seems to already have the best place. Every change in position weakens the tone even more.

Replacing hammers is not an option at this time, so I have to find a solution with the given circumstances. Any help is really appreciated. If it's helpful I could post an excrept of the concert.

[vernon]

If there is a short sustain I cannot ascribe it to any of the reasons you suggest and I can't think that the work you have done can effect it.. It would suggest an inherent constructional defect.
If the initiation of the string is achieved then logically the transference of the "sustain" through the bridge to the soundboard to the ear is being weakened somewhere along that train. Hence, my suggestion of structural problems. Perhaps loose bridge or loss of bearing.

[Colin Nicholson]

Fully agree Vernon. Nothing to do with tuning/ hammers / toning / servicing / key bed.... this sounds like a major defect in the soundboard losing its crown, hence loss of down-bearing near the bridge, or negative (up) bearing at the agraffes/ da capo bars. If the soundboard has lost crown, the bridge will "sink" with it - greatly reducing sustain power on the strings; however could be the bridge coming loose, but under huge tension, the only way to see/ test it is to remove the strings. A bearing gauge may also help. If the piano is quite young (less than forty years old?), may suggest room temperature or humidity problems, however, loss of bearing is not a quick fix - it's major restoration I'm afraid if most of the strings are losing sustain.

About 2 years ago, I came across this problem with an upright piano, about 3 notes gave off a "thunk" when struck - no sustain.
Turned out to be rotten fruit in a wicker basket (a banana I think) on the piano had leaked its juices through the top lid hinge, then dripped down the tuning pins & strings, then formed some kind of "acid bond" around the up-bearing points (upper bridge/ agraffes? .... can't remember which).... strings replaced, about 3-4 tri-chords, and it was all sorted.

Other problems with grands is a build up of dust under the capo bar, and clumps of dust can act as a secondary damper.... a classic case was when I tuned a Weber 2 weeks ago. Piano started to lose its tone/ sustain power - cleaning out improved it a little, but I told the customer to suspect down-bearing loss - well, this piano is about 90 years old.

[RWAS]

As Boston pianos did not come onto the market until 1992, it is unlikely that this loss of sustain is caused by the aging of the piano. However, the extent of the sustain loss suggests that there is a soundboard failure that could be caused by humidity and or temperature extremes or even some violent jolt in moving the piano. In that instance, I think that there would be other evidence of damage.
If the Boston GP 193 is still under warranty there is the chance that it could be repaired free if the problem is an inherent defect. Any repair to the soundboard would virtually involve a complete rebuilding of the piano. That is disappointing for the owner(s).

Kind regards,
Robert.

[joseph]

I'm coming to this late:

I have always found that Boston pianos had a short sustain, as you describe, particularly on the models which pre-date the Performance Edition. The Performance Edition seems to be much better, but I've only ever played the first generation of the P.E models and not the new ones.

Interestingly enough I've played many Kawais which have a similar problem, especially those made in the 1980s - early 2000s. I had a KG-2 and it had lots of sustain, but many of the later models I came across just sounded kind of dead.

In most cases these pianos were nearly new at the time I played them (the Bostons and the Kawais) and so I'm presuming the flaws were there from the outset.