Klarinet Archive - Posting 000192.txt from 2001/02

From: Grant Green <gdgreen@-----.com>
Subj: Re: [kl] Re: difference tones
Date: Tue, 6 Feb 2001 18:12:56 -0500

>Labadorf@-----.com wrote:
>
>What is the difference tone when two persons are playing an octave?
>
>David

You can calculate the difference tone by subtracting the frequency of
the lower pitch from that of the upper pitch. The effect is not very
noticeable when you play in octaves, because the upper pitch is
exactly twice the lower pitch, which makes the difference tone a
unison with the lower pitch.

The difference tone if the pitches played are a fifth apart is an
octave lower than the lower pitch (for example, if you play A4 and
E4, the difference tone would be A3). If the pitches are a fourth
apart, the difference tone is two octaves below the upper pitch
(e.g., if you play A4 and D4, the difference is D2). You can tune
the difference tone by adjusting the pitches you play - increasing
the spread of the interval (raising the upper pitch or lowering the
lower pitch) raises the difference tone pitch, and vice versa.
Difference tones are sometimes used in pipe organs for the lower
pedal notes: e.g., instead of having a rank of 64' (or 32') pipes,
you may find a "resultant" voice that actually consists of shorter
pipes played at a fixed interval to produce the desired difference
tone.

Grant

++++++++++++++++++++++++++++++++++++++++++++++++
Grant Green gdgreen@-----.com
ecode:contrabass http://www.contrabass.com
Professional Fool -> http://www.mp3.com/ProFools
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