Singing rims

[RobertD429@aol.com]

> When
>I went over to the long side of the case and lightly rested my fingers on
>it, I could feel the entire case vibrating from just that one string! Even
>though that was 20-25 years ago, I can still remember the feeling of awe
>I experienced as I listened to that piano sing. It was my first introduction
>to a truly great piano. Try this test. The next time you see a Samick, have
>someone play a 7-8 note chord and hold it down. Now lightly rest your fin-
>gers on the long side of the case. What do you feel? Nothing, nada, zip.
>The truth is that junk woods don't sing.

You've listed two possibilities -- I think there are three, which have to do
with the impedance of the rim. 1) Impedance close to that of the soundboard:
The case can resonate at musical frequencies, becoming part of the sound
transducer. This is a more European approach, made for smaller concert halls
with more reflective walls. 2) The case can absorb and dissipate energy
quickly (low impedance: imagine a rim made of pillows), which is what you are
concerned about. 3) The rim can reflect energy back into the board (high
impedance), which is what Steinway and others with dense maple rims are
shooting for, in hopes of greater power and sustain.

I don't think a resonant rim is necessarily a sign of a great piano -- just a
different approach to design for different conditions.

Bob Davis