Klarinet Archive - Posting 000061.txt from 1997/06

From: Karl Krelove <kkrelove@-----.com>
Subj: Re: Mouthpiece Table Concavity and Ligatures
Date: Sun, 8 Jun 1997 07:59:13 -0400

At 08:19 PM 6/4/97 -0400, Jerry Korten wrote:
>... I think the motivation for this design
>had to do with the ligature in current use (string) at that time. (String is
>still used by some I know.) I think there is an interaction between ligatures
>and mouthpiece table concavity that plays an important role in a succesful
>mouthpiece/ligature combination.
>
>While I agree w/Mr. Fobes that from a mechanical standpoint, it is far easier
>to get a reed to seal against the table at the point the window opens with a
>slightly concave mouthpiece table. Dr. Gibson points out that the design of
>the Zinner mouthpiece actually acts to provide a "spring board" effect to the
>reed. In fact pushing down at the point of table concavity (by the ligature)
>has the effect of bending the reed up and widening the gap between the reed
>and the mouthpiece at the tip of the reed.
>
>I'll throw out a hypothesis that the original intent of concavity as
>implemented on early German clarinets was to get a taughtness to the string
>ligature. That is if you flex the reed while tightening, the string will
>remain under higher tension than if one wound string around a non-flexing
>reed.
>
>
>Jerry Korten
>
Has anyone with better measuring equipment than I could come up with
actually measured the degree to which the reed is actually flexed into the
concavity on these mouthpieces? I've always heard about the "springboard
effect," and I've never seriously questioned it or the notion that the reed
will seal more reliably against the mouthpiece with a concave table. But as
I sit here reading the current posts and pondering it a little, I'm
starting to get uncomfortable with the idea that a piece of wood that thick
could actually be bent into a space that short (relative to the reed's
total length) with the amount of force a human thumb could exert while the
player wraps the string, or with the amount and direction of the force that
would be exerted by a ligature of any construction when it presses on the
reed over an area beginning and ending beyond the concave area. Most of the
ligature force, it seems to my imagination, must be exerted where the reed
contacts the mouthpiece, i.e. at the top and bottom of the concave area,
especially if the force is being supplied mainly by screws that are at the
top and bottom of the ligature. Has anyone actually been able to quantify
the reed's deflection from a straight line?

Karl