One of my churches built a new building some years back. The sanctuary
was poured concrete, bare walls, and octagonal in shape. Four pairs of
hard parallel reflecting surfaces at 45?? angles to one another. C-8 on
the piano produced 1-1/2 seconds of tone and another 3-4 seconds of
echos. I've never seen anything like it. The sound (anywhere in the
scale) immediately swelled and blended as echos overlapped and after a
second or so it sounded like a psychotic toy organ instead of a Yamaha
C-6. The echos continued long after the dampers had stopped the strings.
A hand clap quickly blended into an extended tone as echos mixed, and I
wish I'd have gotten to hear what it did to the choir, but never got the
chance. Unfortunately, I did get to hear what it did to the tuning
process for a couple of years while they attempted to work something out
with the "architect". Wow! Vast amounts of additional money and a whole
lot of acoustical panels later, and it became tolerable, though still
lively. Woody knocks never had a chance.
Ron N
Original Message------
Fred-
Great comment!
I have tuned in an auditorium where there was a double reverberation because of a very steep and deep balcony.
The solutions were to turn the piano 90 degrees so the sound projected into the wing or when possible, to close the fire curtains.
Similar things can happen when there is a plate glass window in a large room.
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Ed Sutton
ed440@me.com
704-536-7926
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Original Message:
Sent: 10-28-2014 10:46
From: Fred Sturm
Subject: Yamaha GH1 Woody Treble
I guess my own question would be whether this is "normal" or "abnormal" woody sound. I know that when I have tuned within a very resonant, reverberant room (gym in particular), the woody attack component overpowers the pitch of the string, to the extent that it is hard to hear pitch. Usually, at the same time, the pitch lingers as well, so that it is doubly hard to tune because you are listening to time lapse: the past is still with you, and you don't hear where you have gotten to until it is too late.
There are a lot of components. Obviously bad keyframe bedding can add an additional knock, but even if it isn't there, there will be keybed knock as the key bottoms out. That noise does enter the soundboard as well (as noted in the Giorgiano article on longitudinal waves, cited in that lengthy Pianotek thread). That is, the bridge moves in part at a frequency probably produced by keybed knock. There is also the hammer knock. It is a good idea to isolate the woody sound by playing the note hard while muting the string. That will tell you a lot about what the space is doing to amplify that sound (mostly by reverberation - it doesn't really amplify it, but the sound doesn't decay like it should in a good acoustical situation).
If you want to see whether it is a matter of hammer mass, you can move a light hammer from, say, note 80 to note 65, and listen to the difference (obviously string grooves need to be addressed to make this a good test). For keybed noise, you can change out a couple front rail punchings for new and different styles.
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Fred Sturm
University of New Mexico
http://fredsturm.net
"When I smell a flower, I don't think about how it was cultivated. I like to listen to music the same way." -Federico Mompou
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Original Message:
Sent: 10-27-2014 14:40
From: James Kelly
Subject: Yamaha GH1 Woody Treble
Wow... some great responses especially from Don. In one sense the piano is what it is. Certainly some of these suggestions will tame a little of the the beast but I do not have a big budget to blow. I will do what I can and address the bedding and a few other things. I like the idea of soaking some of the shanks with CA to stiffen them and may try it randomly. I got some good responses on the Pianotech forum as well.
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James Kelly
Pawleys Island SC
843-325-4357
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