weird, WEIRD, Tokai

[Terry]

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Tom Sivak wrote:

I tune a Tokai grand at a local banquet/convention center, although =
rarely.  This piano has been neglected since it was bought, probably =
some time in the late 80s/early 90s.  As I was tuning  it,  I found that =
the damper on B5 didn't lift, making it difficult to tune, so I =
depressed the damper pedal and indeed the damper did lift with the =
pedal.  So, now being able to sustain the note, I struck it again, =
preparing to tune the note.

WOW.

It seemed as if every note on the piano vibrated in sympathy.  I mean, =
it sounded exactly like someone took their fingernail and with the =
dampers lifted, scraped all the strings allowing them all to vibrate.  =
Now, I know you get some sympathetic vibrating strings when you strike a =
single note with the damper pedal down, but THIS WAS DIFFERENT.  This =
wasn't just a few strings in the overtone series vibrating along.  This =
was the sound of EVERY STRING ON THE PIANO.  Or at least all the steel =
strings in the middle section, because when I struck it again, I took =
the palm of my hand and muted as many strings as I could in the middle =
section (that's all I could reach) and the sound went away. =20

All those strings were somehow set into vibration by the striking of =
this one key.  And it wasn't just that key, it was any key in that =
section.  I was in a rush so I didn't do any further experimenting, such =
as seeing if the same thing happened when I struck a note in the bass, =
for instance.  I didn't plan on the extra time to repair the dampers (I =
found two others that didn't lift) and it was one of those days that I =
HAD to stay on schedule.

I wonder if any of you have a theory as to what's going on here?=20

I have observed a similar thing when tuning a piano. My assumption has =
been that it sounded so weird simply because of the fact that I was =
engaged in tuning, I was listening to things very closely, and all the =
other strings that were singing were that much more noticeable. That's =
my theory.

I don't think it's an acoustical phenomenon.  I think it is mechanical.  =


I'm not an engineer, but it seems to me that acoustical phenomena often =
are the result of mechanical happenings. Like a hammer hitting =
(mechanical) a string and making noise (acoustical).

I think somehow the bridge is transferring energy/vibrations to the =
other strings. =20

Indeed. This is one of the things bridges do best. The played string =
vibrates the bridge and the bridge in turn vibrates the nearby strings.

Or maybe the soundboard somehow activates the other strings to vibrate.  =


That too I suppose, but I imagine that most of the energy received by a =
sympathetic strings would stem from the fact that it is coupled to a =
vibrating bridge.

I don't know...I'm talking nonsense here...but what the heck could be =
happening?

Let's hear what some experts have to say here.



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