Klarinet Archive - Posting 001202.txt from 1999/05

From: James Pyne <jpyne@-----.edu>
Subj: [kl] Even Partials (was Bradley's Question)
Date: Thu, 27 May 1999 02:23:38 -0400

Dee Hays wrote:

>I did see an article on this but unfortunately can't remember where. The
>gist of it was that it is only in recent years that the spectrum analyzers
>have been good enough to indicate that even number partials are present.
>They are very, very weak and so for the practical purposes of playing they
>can be considered non-existent.

>Dee Hays
>Canton, SD

The even partials (2,4,6...) are abundantly present in the spectra of
clarinet tones. They are physically measurable in the air borne sound and
do not exist as a function of non-linearity in the hearing mechanism, as is
thought to be the case with difference tones.

I'm looking a computer FFT visualization of a clarinet tone now, using
hi-level scientific measurement software on Macintosh. I will read out the
values of the harmonics (partials) below.

Performer - Clarinetist from the Toronto Symphony (Bb soprano clarinet)

Performed tone is - written 4th line D - sounding C5

partial 1 - 523Hz - 90 dBVrms

partial 2 - 1046Hz - 75 dBVrms

partial 3 - 1569Hz - 80 dBVrms

partial 4 - 2092Hz - 62 dBVrms

partial 5 - 2615Hz - 64 dBVrms

partial 6 - 3138Hz - 62 dBVrms

partial 7 - 3661Hz - 55 dBVrms

The clarion and altissimo registers have powerful even partials. In some
cases showing peaks higher than their odd numbered neighbors. The chalumeau
register (especially low chalumeau) shows more suppression (not
elimination) of even partials, especially partial 2 and to a lesser degree
4 and 6. However, as we certainly know, the clarinet will not cooperate in
overblowing at the frequencies of these even partials.

---Jim Pyne

James Pyne, professor
Clarinet Studio/Research Group
School of Music
The Ohio State University
1866 College Road
Columbus, Ohio 43210
pyne.1@-----.edu
Tel: 614 292 8969
Fax: 614 292 1102
http://www.arts.ohio-state.edu/Music/Clarfest

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