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Re: Moennig Barrels won't slide on

Author: shmuelyosef
Date: 2017-12-06 07:58

This is a great example of what is wrong with our expectations of barrels and intonation.

In reality, if a barrel were perfectly fitted (i.e. with the socket depths exactly matching the tenon lengths so that there is NO gap), then the operational length is simply the distance between the machined flats in the sockets...typically somewhere near 30mm for an average Bb clarinet. Only in this situation, is it useful to think of a barrel that is 1mm longer or shorter (as measured end-to-end as is the custom) as changing the intonation in a predictable manner. Remember, the intonation (like a mouthpiece) is determined as much by the volume as the length.

For example, a Gedanken experiment:
----Imagine that you have a manufacturer supplied barrel that has a 1mm gap in the joint socket end and has (typical of an R-13):
- a socket diameter of 21.7mm
- a bore diameter of 15.65 mm
1mm of bore length corresponds to about 0.19cc volume, while 1mm of socket length is about twice that...or 0.37mm. So with respect to bore volume, 1mm of bore extension (the inner part of the barrel) has half the effect compared to 1 mm of socket extension!

In my experience, most stock barrels have between 0.5mm and 1.0mm of 'gap' at the socket ends (adding the gap at both ends together). It is easy to test this with some 0.5mm tuning rings. Put them in both ends of a typical barrel and you will likely find that one or the other end will close up fully. You may also notice in this configuration that the barrel will now play a little sharp compared to no tuning ring...the total volume is now less.

Roxan, you should check this out to see if your stock system is 'fully closed', i.e. no gaps in the socket bottoms.

The flip side of this is that such a discontinuity in the bore can be a tuning feature...this is the fundamental concept around reverse taper barrels (like Moennig) where the design creates a discontinuity between the barrel and the upper joint that forces a 'node' in the harmonic structure of the bore. Similarly these gaps in the joints create (sometimes unintended) discontinuities in our bore, and can happen at the middle socket/tenon as well.

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