Klarinet Archive - Posting 001025.txt from 2000/03

From: Jonathan Cohler <cohler@-----.net>
Subj: [kl] Reed Vibration
Date: Fri, 31 Mar 2000 08:29:07 -0500

There is no mystery or controversy over how reed vibration works on a
clarinet. It has been very well understood for decades now.

In a nutshell... When you blow softly (below what most people consider a
"mf" dynamic level), the reed tip vibrates without touching the mouthpiece.
As you get to the "mf" level, the reed begins to hit the mouthpiece for a
brief portion of it's cycle. This hitting the mouthpiece, generates more
high frequency energy in the driving waveform, which in turn excites more
of the higher frequency modes of the air-column, which in turn generates a
"brighter" sound. One can hear this change in the tone color (all of this
is described in detail in Benade, "Fundamentals of Musical Acoustics).

As you get louder, the reed hits and stays against the mouthpiece for a
longer and longer portion of the reed vibration cycle. This adds ever more
brightness to the clarinet sound. This is why the tone color of the
clarinet changes with loudness, and why the clarinet can have such a richly
varied tonal pallette.

Now, the point at which the hitting begins (the "mf" that I mentioned
above) depends heavily on several factors:

1. How wide your tip opening is.

2. What strength reed you are using.

3. How hard your lip is pushing the reed in against the mouthpiece.

4. The shape of the baffle in the mouthpiece, which determines
the magnitude of the Bernoulli force that sucks the reed in.

5. Blowing airpressure.

Obviously, with any given mouthpiece/reed setup, (3) above allows one to
modify where the hitting point is.

Many orchestra players around the world, prefer to make the clarinet into a
dull monotonic instrument, and therefore control there setup, lip and
blowing pressure to avoid ever reaching the "reed-hitting" point. They
tend to:

* Play on hard reeds (which also generate a large amount of white
noise)
* Use mouthpieces with small openings and low Bernoulli forces
* And they never play above "mf"

As an aside, there is large contingent of people who have been misguided
into thinking that the white noise generated by too-hard reeds generates a
somehow "darker" sound. This, of course, is poppycock. White noise is,
very simply, noise -- an undesirable random, and annoying sound.

However, if you would like to truly make the clarinet sing with a wide
range of dynamics and a widely varied tonal pallette, the only way to do it
is to make use of the full range of the reeds "striking" possibilities!

-----------------------------
Jonathan Cohler
cohler@-----.net

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