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Over tones on isolated notes

  • 1.  Over tones on isolated notes

    Member
    Posted 10-24-2023 12:55

    I have two newer Boston pianos, a grand and an upright that have a very prominent ring in just 2 notes in each piano. In the grand is in the bass wrapped strings and in the upright is is G#3 and A3. I have tried leveling the strings, mating the hammers, voicing the hammers and checking for loose braiding in the waste ends. Nothing has had any effect on the overtone ring.

    Does anyone have any suggestions as to what I should check 



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    Rex Roseman
    Norton OH
    (330) 289-2948
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  • 2.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-24-2023 13:16
    Make sure all the dampers are seated on the strings and there is follow through on the dampers. You can easily check this when pressing the damper pedal. If the dampers rise the instant the pedal is pushed down, changes are that the damper felts are just barely resting on the string, creating overtones. 

    Wim





  • 3.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-25-2023 07:39

    Rex,

    Have you confirmed by testing that the ring is coming from the physical notes in question, or could the ring be being generated by the notes yet be coming from somewhere else?

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 4.  RE: Over tones on isolated notes

    Member
    Posted 10-25-2023 09:07

    Is it a metallic like ring or is it and after sound as an undampped string ? If it is a gong like sound you may need to add some more mass to a plate strut by using some strong square magnet. Damper leak may require some delicate bending of the damper heads to get equal felt fit especially if the damper felts are two piece. Make sure there is enough lost motion in the damper pedal . On the upright check for damper follow through by pressing on the strings to see if dampers move forward. You may need to bend the damper wire toward the strings at the base of the damper head. On the grand check the center pinning friction on the damper flanges, remove and polish, lubricate the damper guide wires for the two notes but keep in mind other notes could be leaking. Use a mirror to observe how the rear damper felt is sitting on the strings.   By any chance does the Boston Grand have a player system ? If so regulating the dampers is challenging



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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 5.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-25-2023 13:07

    It's always important to isolate exactly where it's coming from, otherwise you're chasing your tail. If you play and release the note, ringing occurs...if you put your finger on the unison and it immediately stops younknow its a damping issue. If it continues, its somewhere else. If its in the unison, which string(s) are generating it? Eliminate things till you isolate the specific problem. Then you can address it. (Treat the problem not the symptom). 

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 6.  RE: Over tones on isolated notes

    Member
    Posted 10-25-2023 20:50
    Thank you for your good suggestions. Some more information about what was observed. In both cases, the extra sound was very high pitched and only on one note and less on the lower neighbor. I isolated each string and all of them produced the sound individually so it is not a single string. When I have had dampers not stopping strings completely, the tone of the poorly dampened string appears at each of the overtones to some degree. If it is say a low C that is the problem, it will show at the next C up, and the G and the next C... This is isolated to two notes and is not producing a harmonic elsewhere.

    The diagnostic ideas were good and will be helpful later.

    How much magnetic weight needs to be placed on the strut to cause a dampening effect?

    I will try some of the ideas when I have a chance to see the pianos again and let you know what I found.

    Thank you.





  • 7.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-26-2023 16:59

    Rex,

    A fast way to isolate the problem is to use masking tape, put the tape across all the strings then remove till you locate the problem

    It sounds a little like what Steinway had a few years ago, the damper felt was too soft.

    John



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    John Zeiner RPT
    Warrington PA
    (610) 390-1605
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  • 8.  RE: Over tones on isolated notes

    Member
    Posted 10-26-2023 19:48
    John

    I think that there was some confusion when I described what I heard as overtones. There is no leakage from dampers. The high pitch sounds are very prevalent and only last as long as the note is sustained. When the note is released everything damps completely, including the offending sounds. No other notes in the pianos have this high pitch ring.





  • 9.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-27-2023 18:05
    How does it sound when you pluck the string with your finger? This isolates the sound coming from the hammer vs coming from the string.
    Stewart

    Sent from my iPad




  • 10.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-27-2023 19:02

    Rex,

    The high pitched ringing (pulsating maybe) is likely a longitudinal mode issue. And it's going to be really hard to eliminate. What you might try is carefully straightening all bends in the wire from the hitch pin to the tuning pin. This can subtly change the speaking length of the wire and can change the way it vibrates, thus POSSIBLY change the L mode situation. It may not, but it's worth a try. 

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 11.  RE: Over tones on isolated notes

    Member
    Posted 10-30-2023 10:10
    Stu

    I am not sure if I did that check. I did pluck each string individually when checking for hammer mating, but don't remember if I paid any attention to the ringing sound. I will definitely make a not to to that test the next time I am there.

    Thanks for the reminder.





  • 12.  RE: Over tones on isolated notes

    Member
    Posted 10-30-2023 11:26

    Regarding magnets go to Harbor Freight Tool and buy two of their magnetic tool bars. You can do a fast check with a full length bar laying it on of the strut to see if it has an effect. You can then cut various lengths from the other tool bar and experiment with them. There are no specific gram weights - you need to experiment. 



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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 13.  RE: Over tones on isolated notes

    Registered Piano Technician
    Posted 10-30-2023 19:52

    My experience with plate strut ringing tends to be in the lower frequency range. Often it's the long strut at the bass/tenor break that vibrates. When it gets ugly is when the strut frequency is very close to that of say a bass note, such that it sets up a beating that pulsates in an annoying manner. Once you tune in to it you can't not hear it. That's when I put weights on to lower the frequency out of the annoyance range. What Rex is talking about does not seem to fall I to this category from what I've read.

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 14.  RE: Over tones on isolated notes

    Member
    Posted 11-03-2023 20:28
    Thank you everyone who responded to the initial post. I had a chance to get back to the piano upright today and can report back what I found.

    First, I checked the strings by plucking them to see if I could isolate the sound to the strings or the hammers as Stu suggested. Unfortunately, the difference in sound caused by the plucking vs. the hammer made it hard to make a determination if it was the string or the hammer.

    Second, I checked the terminations and tightened the bends at the bridge and the tension bar as was suggested as a possible way to change longitudinal vibrations. This stabilized the strings more, but did not change the sound.

    Third, I did some more voicing with no affect.

    Fourth, I added weight to the plate struts with the magnet with no affect.

    Finally, I decided to try putting in the pitch-lock clips on the offending strings. This seemed to dampen the extra noise and had the most effect of anything.

    I am not 100% sure that the problem was "fixed", but it was greatly mitigated and the pianist is going to report back what she thinks as she plays it.

    That's where we stand with this. Thank you to all that replied.