Klarinet Archive - Posting 000196.txt from 1998/04

From: Bill Hausmann <bhausman@-----.com>
Subj: Re: THE REED'S MODE OF VIBRATION (END)
Date: Sun, 5 Apr 1998 19:28:11 -0400

At 04:44 AM 4/5/98 -0400, Avrahm galper wrote:
>The Reed's Mode of Vibration (McGinnis and Gallagher)...
>RESULTS
>1) During a large part of its cycle, the flow of air into the mouthpiece
>is completely cut off by the reed This is more obvious visually.
>The only source of light used in making the photographs was the mercury
>arc of the stroboscope, which was placed to show particularly the slit
>between the reed and mouthpiece.
>This complete closure of the reed apertures is in disagreement with the
>assumptions that the chink between the mouthpiece and the reed never
>shuts completely.
>
>It also conflicts with statements that the clarinet reed never entirely
>shuts off the ingress of air into the mouthpiece while the instrument is
>sounding.
>
>2) The motion of the reed during the complete cycle is of interest.
>Consider that the chink is just on the point of closing.
>With the aperture closed, the reed appears motionless to the eye for
>about half the time of a complete cycle.
>It then leaves the mouthpiece with relatively high velocity and reaches
>its position of maximum displacement in a series of short spurts.
>The time spent apparently motionless at maximum displacement is roughly
>a quarter of the fundamental period
>The tip of the reed now returns to the mouthpiece in another series of
>short spurts, and the fundamental cycle is complete
>Thus the actual motion of the reed occupies only about a quarter of the
>entire period.
>
Isn't this what I said a couple of months ago that created such a furor of
denials? Thanks, Avrahm!

Bill Hausmann bhausman@-----.com
451 Old Orchard Drive http://www.concentric.net/~bhausman
Essexville, MI 48732 http://members.wbs.net/homepages/z/o/o/zoot14.html
ICQ UIN 4862265

If you have to mic a saxophone, the rest of the band is too loud.