Klarinet Archive - Posting 000741.txt from 2002/06

From: Tony@-----.uk (Tony Pay)
Subj: Re: [kl] Modern Basset Horn designs
Date: Sat, 22 Jun 2002 02:37:47 -0400

On Thu, 20 Jun 2002 13:12:24 -0700, leeson0@-----.net said:

> There is an issue that I don't understand relative to Stadler's
> ellipsoid bell because it does not seem to play a role in the low C.
> There is a hole at the top of that bell near the connection to the
> lower joint, and that is where the air comes out for a low C, so it
> never gets to the other end of the bell.

You need a more sophisticated model than that. The *vibrations* in the
aircolumn do persist lower than the first open hole.

As I've said before here, to have a realistic picture you often don't
want to think of air going down the instrument. It's better to imagine
that the air *already in the instrument* is vibrating together with the
reed in a co-operative regime.

> In fact, if you close that hole (with your foot or your calf), you get
> a low B-natural on the instrument because the air comes about about
> 3-4 inches lower than it does for the low C.

Perhaps it's more understandable that the bell *does* affect the sound
of those low notes, even with an open hole above it, when you reflect
that adding or subtracting keys low down on the instrument can have a
very large effect on *high* notes.

For example, G sitting on the top of the stave, and also high C and D,
are altered in quality by the addition of the B key, operated by either
RH or LH little fingers. Similar fingering alterations in higher
registers can have even more extreme effects, involving change of pitch
and occasionally unavailability of a previously available note.

This sort of thing is easily appreciated by anyone who can play the
instrument.

If you further reflect that the quality of any note is determined by the
higher harmonics of that note (which have frequencies that are multiples
of the frequency of the note itself) then it's easier to understand that
a fingering modification that can affect those high frequencies can be
crucial to the quality of the low notes.

So, that's why adding the low E key can have an effect on the quality
of a low B or a low A, even though there are intervening open holes.

And finally, a spherical/ellipsoid bell plus an open hole is analogous
to a rather extreme fingering modification.

Tony
--
_________ Tony Pay
|ony:-) 79 Southmoor Rd Tony@-----.uk
| |ay Oxford OX2 6RE http://classicalplus.gmn.com/artists
tel/fax 01865 553339

...... I'm out of bed and dressed. What more do you want?

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