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On a new upright piano that is freshly tuned, I hear a high pitched chime-like noise specially when I press and release two mid-range notes simultaneously, like B3-flat and D4. The noise is like someone hitting on crystals inside a cave far away, and it rings for short a moment even after I release the keys.

I can imagine this should have something to do with harmonics of other strings being excited. But is there a way to get rid of it? Or is this something that one has to accept as "quality" and has to live with it?

UPDATE:

I opened the case and tried to check the source, it seems that it is not the small strings that are without dampers. I also tried to damp the struck string by hands, but the chime persist.

I made recording which you can listed to the sound here. (You have to bring the volume up you clearly hear the ringing.) I created a time resolved frequency spectrum which is shown here:

Time resolved spectrum

From the spectrum I can see the principal component of the two mentioned notes (D4 = 293.665 Hz and B-falt 3 = 233.082 Hz). But there are the other harmonics that are present all the time, perhaps due to other strings in spite of having dampers.

Can it be that the dampers of other strings are not pressing hard enough?

Or am I just being too sensitive on this?

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  • Your description of the sound sounds to me like the sound my guitar strings make when the ends are not cutt off. I have littel to no experience with real pianos, but maybe some of the strings are not cut and they catch up the vibrations and start to make that sound? (Just a guess)
    – Olli
    Dec 3 '20 at 11:21
  • Thanks. I have actually opened the case and looked inside. Everything is really fastened tight in there, no loose parts nowhere. It sounds as if high pitched notes start to vibrate by themselves somehow.
    – xaratustra
    Dec 3 '20 at 11:28
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    Might be the strike-points (could well be called something else) where hammer hits on string is at 7th harmonic i.e. it cancels out the 7th harmonic. The hammer could be slightly misalligned. With hammer misaligned you will quite clearly hear the 7th harmonic.
    – user70304
    Dec 3 '20 at 14:30
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    The uppermost strings don't (usually) have dampers, so perhaps it's a sympathetic vibration there. But when I've run into this kind of problem, it's usually something else in the room that is vibrating -- it just sounded like it was coming from the piano. The one other scenario I've encountered was on a grand piano where a misaligned string was vibrating against an agraffe.
    – Aaron
    Dec 3 '20 at 14:32
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    Regarding your question about the dampers: yes, it's possible that dampers are misaligned or not shaped correctly.
    – Aaron
    Dec 3 '20 at 21:00
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To find out what's resonating you can try this:

  1. Get one of those small cheap computer microphones on a stick. (Better but not indispensable if it's a directional microphone)

  2. Connect it to a computer or smartphone so you can hear the sound from it

  3. Wear headphones

  4. Play or have someone play those keys while you move the microphone inside the piano, to find out where it's louder, and therefore where it's coming from.

  5. When you get close to it, try damping anything in that area, until you find something that works. Note that you may not be able to see anything moving, but pressing a finger against a particular point might stop or reduce the resonance.

Having said all that, since you mentioned it's a new piano, it's also possible that this resonance will go away by itself after some time, as the whole thing shakes down over time, just by being played.

Update

After hearing the recording, where you play a Bb and the resonance is an F, an octave and a fifth above it, and noticing the resonance has quite a bit of sustain, I'd venture the following guess: the resonance is probably caused by the piano strings themselves, not being completely stopped by the felt dampers.

The resonating string might be the very same string you are playing (Bb), or the Bb above it, or one of the Fs. (Actually, you probably hear a lingering harmonic of the main frequency of the string, rather than the main pitch of the string)

You can easily test it by damping the strings with your finger, or some suitable material. To find out if it's one of the same Bb strings, play that Bb and keep the key down, and stop the sound by manually damping the vibrating string. If the sound stops without resonance, it was that. If the resonance continues, try manually damping other strings, the most likely culprits being octaves or fifths from the main note. But also try octaves and fourths below.

You can also try to gently press down further the dampers against the various strings. If by pressing further down the damper of a string prevents the resonance, that tells you that this particular damper is not stopping that string enough from vibrating sympathetically.

If this is found to be the problem, the solution would be to try and adjust the felt of the damper, so that is presses well enough against the strings, to stop their vibration completely.

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    In addition, as it's brand new, record the noise as you're searching for it & send it to the manufacturer for comment.
    – Tetsujin
    Dec 3 '20 at 13:47
  • Thanks. I tried a recording and put the results updates in the main post.
    – xaratustra
    Dec 3 '20 at 20:39
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    That sounds to me like a harmonic from an insufficiently damped string. See my update above for more details
    – MMazzon
    Dec 3 '20 at 22:31
  • Yes, that seems to be it. It is now clear to me that it is the dampers that are not pushing hard enough. I recorded a new sound sample, this is G2-G3 octave and can be heard here generally it seems to happen in the range G2-C5. I contacted the dealer they told me it is nothing serious and can happen due to transport that the mechanics might move. They suggested to leave it for a couple of weeks until they come for the service tuning, which is already paid in advance with the brand new instrument.
    – xaratustra
    Dec 4 '20 at 13:58

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