Are there any known instruments (8+4 or 8+8+4) where the 4-foot jacks
don’t have dampers?
Thanks.
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If I remember well, the single manual harpsichord by J.C. Fleischer, Hamburg 1710/1724, Musical Instrument Museum, Berlin. It is unusual for having three rows of jacks of which two control the same 8’ string choir at different plucking points. As for the 4’ jacks, they never had dampers.
I also remember having seen some antiques where the 4’ had no dampers for the treblemost strings.
These lacks of dampers help in the “cathedral resonance”, but are an issue for accurate tuning. Since you need to tune the 8’ before the 4’, the still out of tune 4’ strings produce beats that interfere with the tuning, as they may be confused by beats caused by 8’ strings.
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Thanks for mentioning the Berlin Fleischer, Claudio.
I don’t think this is an issue for tuning, any more than side dampers
are. I’m used to tuning instruments with side dampers, and the plucked
notes are much louder than the sympathetic vibrations, so there’s no
confusion.
Le 17/01/2023 22:14, Claudio Di Veroli via The Jackrail écrit :
Yes, it is quite common for the dampers on one or all registers to be ‘out of action’ unless the register is being played. However this is not a tuning problem. The undamped string resonance is driven at the frequency / frequencies of the string that is being plucked and tuned. If the non-sounding string is out of tune it will simply not resonate. There is no situation where you get beats involving a string that is only resonating, not being plucked.
At most the presence of undamped out-of-tune strings could amplify some ‘unexpected’ harmonics of the strings that are being tuned.
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Thomas, Dennis, indeed it was not an issue when I was a young and active harpsichord tuner. Now that I am in advanced age and only tune my harpsichord, and my hearing is not what it was, it is more of a problem.
French Baroque also thought so. For a French double, they recommended (I can recall at present Corrette’s directions) tuning first the upper 8’. Hubbard (wrongly, influenced by flag dampers) thought this could be for the different harmonic contents. It is obvious that the cause was another: when you tune the upper 8’, you can leave the lower 8’ and 4’ stops ON, thus dampened by historical dampers.
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“However this is not a tuning problem. The undamped string resonance is driven at the frequency / frequencies of the string that is being plucked and tuned. If the non-sounding string is out of tune it will simply not resonate.”
I’m no expert, but it’s clear to me that this will be a tuning problem. “If the non-sounding string is out of tune it will simply not resonate” – unless the string you’re trying to tune gets close to the wrong pitch of the other string! I.e., you’ll get false “confirmation” at a pitch near the correct one, and as you move closer to correct pitch, the resonance will dissipate. This seems likely to be confusing and most unwelcome.
Not exactly the same situation, but rather similar, is tuning a 12-string guitar. It is absolutely necessary to damp one of the two strings in each pair (whether at octave or unison), to get the other one into tune initially. The sympathetic resonances are a confusing hassle until everything is in pitch. Actually, the worst problem is not beats, it is that when the two strings are closer than a certain pitch difference, the two pitches “phase lock” together, beating stops, and suddenly the string you’re trying to tune starts to behave strangely, almost “reluctant” to change pitch even though you’re cranking on the tuning key. Then you finally move the tension far enough, and boom, the strings drop out of lock and suddenly you’re many cents sharp.
–Benjamin
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Wow, I am fascinated with the various responses to this topic. I tune harpsichords all the time, both antiques and modern reproductions. There are probably 50+ instruments I see and tune relatively regularly in the greater New York City area and in Delaware. I have NEVER found undamped unison or octave strings to interfere in the least when tuning. The only problem I have is when a quill is just a little too long in the register’s “off” position and it ghosts. Then that quill has to be cut back. But that’s it!
The guitar case may be special due to the very strong coupling between adjacent strings at the same pitch - is it even possible to play one but not the other without putting on some sort of damper?
Still, for the harpsichord you in practice don’t have this problem, probably because of the much bigger mass of the bridges, case etc; or it is confined to tuning the same note on two 8’s or an 8’ and a 4’, where you are playing both unison strings at once. Unisons and octaves are a bit of a special case, but this is nothing to do with damping or the lack of it.
To clarify a little further, when tuning a given string you have another string that you are tuning it to (via an octave or third or fifth etc), call this the reference, any ‘interference’ would come from undamped third strings which are not being played.
So you are listening to the string being tuned and to the reference, other strings may resonate at their frequencies or harmonics of them. I don’t think this disturbs the ability to hear beats or lack of them between these frequencies and harmonics. And the notes produced directly by the plucked strings should indeed be louder than anything else.
I only tune one instrument with 4ft strings. The dampers are “triangular”, so disengage when the register is off. I also have never encountered any interference when tuning the 8ft strings.
David
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Le 20/01/2023 09:37, David Pickett via The Jackrail écrit :
I only tune one instrument with 4ft strings. The dampers are
“triangular”, so disengage when the register is off. I also have never
encountered any interference when tuning the 8ft strings.
I currently have three instruments with “side” dampers, and I also have
never encountered problems tuning them. I have even never encountered
anyone who has had such problems.
A unison or octave (which is a unison at the second partial with the lower note) do not have to be perfectly tuned for sympathetic vibrations to exchange energy.
As a professional tuner (mostly piano, sometimes harpsichord) I habitually scan the overtones when tuning unisons. When the 4’ was close, but not quite, I often heard a bit of sympathetic interference at the second partials of the 8’s when tuning 8’ unisons. Not a lot. Something I could ignore once I recognized it, but I would have been happy for it to go away.
It goes away when the 4’ is tuned dead on.
And one might question whether a perfect unison and 4’ are historically correct.
It can be argued, and sometimes demonstrated, that a very slightly imperfect unison sustains longer than an absolutely pure unison as the pure unison does a better job of moving the soundboard and releases the energy of motion to the air more quickly.
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