Klarinet Archive - Posting 000864.txt from 1997/05

From: Jrykorten@-----.com
Subj: Re: Ligatures - OK Please explain
Date: Fri, 30 May 1997 09:24:50 -0400

I too believe that the plating is too thin a substrate to propigate the type
of vibrations that could couple from a reed. The only thing that I can think
that ligatures in general can have, as far as an effect on reed behavior, is
energy that is or isn't reflected back into the reed. Coupling the body of
the reed mechanically to the moutpiece table should be equally well handled
by all the ligatures on the market I see. But, using a rovner instead of my
old bonade, I can tell the acoustic difference between these designs easily.

There are mechanical considerations that I think (more importantly as many
manufacturers think) impact on the reed when coupled by a ligature. And one
is the pressure on unsupported reed surface. That is the edges on the lower
half of the reed that extend beyond the moutpiece table. For that reason the
raised rail system used in the bonade and now by others works well. I sand my
reeds in a taper so that there is no unsupported surface under a rovner
ligature.

(I also think that reeds are manufactured too wide at the tip of the
mouthpiece and should generally be sanded down to the width of the rails.)

Anyhow none of these are under the influence of plating material.

So perhaps the softer metal (at plating thickness) can't reflect energy the
same way? (I'm really trying to be generous here.)

Jerry Korten
NYC

In a message dated 97-05-29 17:50:37 EDT, Stephen writes:

<< From a fizix point of view, only the highest modes of the reed
should be damped by the ligature. Also, do reeds have any tortional,
compression, or off-axis lateral modes? I would think these are all
important in the higher harmonics.

Note: if there are other modes that are very important, they should behave
quite differently (except for tortional modes) in string or leather
ligatures.

All of this said, I really have no clue. I can but guess from my
limited knowledge where the energy of those higher modes goes. In other
words, besides being primarily coupled to the air column, what is the
second order coupling of the reed? Is it the ligature or the mouthpiece?
A good indicator would be the speed of sound in the two materials. Again,
the CRC handbook is the place for such things, except I don't know if they
list polymers, as they're so hard to charactize.

Sincerely,
Stephen Froehlich

>>