Bridge Vibration... was Wapin Revisited

[Ric Brekne]

Hi JD

AH  but it DOES move !  Dr. Birkett and I looked long and hard with some decent resolution and a couple of inlayed markers to confirm that.  Just how much it moves... and to what degree it is in sync with the string pulse tho was less clear.

I supposed that perhaps the two vibrating planes of the soundboard and stringset might somehow trap (at least to some degree) the bridge inbetween. That may sound very strange to some... and indeed might not be the case... but it seemed fairly clear that the vibration of the bridge we could observe was not  in synch with the period of the string pulse. By the time the strings vibration had dissapated into a more or less standing wave state.... I couldnt detect any bridge vibration any more... tho I kind of have to think there was.

It did raise ones desire to examine (in this fashion) the whole question more closely. As time goes by faster and better equipment will be available at far less expense then at present and we no doubt will get better answers.

Cheers
RicB


JD copies and writes:

>You can see some of Dr. Birkett's high-speed videos here (note you 
>may need a special plugin for it to work):
><http://real.uwaterloo.ca/~sbirkett/high%20speed%20imaging.htm>http://real.uwaterloo.ca/~sbirkett/high%20speed%20imaging.htm

So much for "movement" of the bridge :-)

JD