I have never tuned one of these.
However, as the point of those notes is sympathetic vibration, I would simply do what I do on most any resonant piano; lift the dampers and tune the monochords to the resonance of the open belly. One does not listen for partial matches, but coming from below, find the spot where the whole belly takes off, (dampers up).
One has to ask what in-tune means down there, as the notes are not part of 99.9% of piano lit repertoire. I would suggest that in-tune means doing whatever is necessary to maximize the sympathetic resonance of the entire instrument. Its probably pretty easy on these guys, with less listening for phantom partials, and presence of more real fundamental.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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Original Message:
Sent: 10-04-2017 11:18
From: John Formsma
Subject: Bosendorfer extra bass notes
I've only tuned one Bosendorfer like this (tuned it many times). Since I've been an aural tuner for many years before using RCT, it wasn't very hard to tune them aurally. Helps to remember hardly anyone will use them, and almost no one will care what they sound like. Mine sounded good, but still...a reality check helps.
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John Formsma, RPT
New Albany MS
Original Message:
Sent: 10-04-2017 10:25
From: Alan Eder
Subject: Bosendorfer extra bass notes
1) By touching the strings at their mid-way point to elicit the second partial, or;
2) With the latest version of Reyburn CyberTuner, which has a feature for tuning those four to nine extra notes (Stuart & Sons, too).
Alan
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Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
Original Message:
Sent: 10-04-2017 10:16
From: David Weiss
Subject: Bosendorfer extra bass notes
Good morning. Can someone tell me how to tune the extra bass notes on a Bosendorfer?
Thanks,
David
David Weiss Piano Service
Sent from my iPhone