Ya don need a Bosendorfer?

[Kent Swafford]

On Thursday, May 15, 2003, at 04:18  PM, A440A@aol.com wrote:

> Ideas, anyone?

Difference frequencies are difference tones when the difference 
frequency is in the audible range.

Difference frequencies are beats when the difference is a frequency 
below what we can hear.

The two are the same phenomenon. All pairs of frequencies produce both 
sum and difference frequencies.

The partial series provides an easy way of locating the notes of the 
scale where one might look for difference tones.

3-2=1
The difference frequency formed by the fundamentals of a fifth will be 
found one octave below the lower note of a fifth. Example: In terms of 
ratios, to form a difference frequency at C3, play C4 (twice the 
frequency of C3) with G4 (three times the frequency of C3). If the 
frequency of the top note of the fifth G4 is "3", and the frequency of 
C4 is "2", then the frequency of C3 will be "1". (3-2=1)

4-3=1
To form a difference frequency at C3, play a fourth G4-C5, with the 
difference frequency two octaves below the top note of the fourth.

5-4=1
To form a difference frequency at C3, play a major 3rd C5-E5, with the 
difference frequency two octaves below the lower note of the third.

6-5=1
7-6=1 and so on.

These frequencies are real, not illusions.

Set an ETD at the fundamental of C3 and play some of the above 
examples. Neither C5 nor G4 alone could possibly produce a moving 
display at C3; play C5-G4 together and you may be able to get a reading 
at C3. It will be faint and won't last long, but it may very well be 
there.

Kent Swafford