My Kawai BL 51 upright, an old one and not of great quality, let's be honest, is giving me an annoying problem: it over-sounds! Every note, even after I have released the key, continues to emit a slight sound, somewhat including harmonics but above all the note itself. Obviously, I think of the dampers, but even if I try to press the damper against the strings with my finger to ensure it makes good contact, the sound continues. I don't know who to turn to anymore?
All dampers must be checked, especially those of the bass notes. One test you can do is to play a note loudly and dampen other areas of the strings with one hand. This will allow you to identify if any area is resonating. If the resonance or prolongation comes from the key being "played", ensure that the damper touches the three or two strings well, or even the single string, and that it does not release too early. In your case, it seems like a case of resonance due to the bass notes. Keep in mind that the first harmonics consist of the fundamental which reappears as many as three times. Therefore, sometimes it may seem that the sound relative to the key being played does not dampen, but it could be a harmonic of the fundamental note (the one being played) that is produced exactly on another string that contains it and is not well dampened. A good technician is needed. A slight general sound decay/tail is not a problem. I hope this was helpful to you. Let me know
P.S. Adjusting dampers properly is difficult; even a minimal deviation of the felt can cause a problem. <not to mention, if the head felts are very old, they might have hardened and become defective and may not rest well against the strings in the resting position. They should be replaced!
Naturally, those for the treble can be replaced in a workshop, but those for the bass ABSOLUTELY must be done in the presence of the instrument. The strings themselves will serve as a perfect guide for the adjustment on the heads, even in the presence of imperfect alignment (referring to the wedge felts for the two strings, those with double wedges at the beginning of the mids, and those for a single string)
I tried to stop the vibration of the notes with my fingers at the 2 upper octaves and indeed the sound drops a little. The fifths can also be heard a bit and all together it goes beyond a reasonable resonance. As far as the felts are concerned, I even have the impression that the damper felts are too soft rather than too hard! I'm going to need a technician!
You are far away, otherwise I would have helped you. Good luck with the work. It could also be that by moving them forward (adjusting the hammers and jacks) you can still make use of the existing ones. If the damper starts immediately, it may be that the felt has worn down so much that, in the resting position, it does not touch the strings. In that case, you must move BACK the hammer that is at the end of the rail. As I repeat, the damper must leave the string at the halfway point of the hammer's stroke. The regulation must be uniform for all keys. You can call a technician for a tuning and see what they think. Let me know
