Jim, It is so great to see you back. I had some questions I wanted to ask about the speed of sound through air. I know it is affected by temperature, but what about humidity, or should I say 'relative humidity'? I am wondering if this plays a role in difference tones? The "difference tone" is very audible (in certain ranges) when tuning a pure fifth that many of the historical temperaments require. There a difference tone in thirds also. If listening to a synthesizer in very good ET you can hear them in fifths and thirds also. On occasion I hear them when tuning pianos (in ET) but not all the time. I always wondered why sometimes I heard these low tones when most of the time I did not. ---ric ----- Original Message ----- From: Jim Coleman, Sr. <pianotoo@imap2.asu.edu> .> I played violin > until 7 weeks ago. It is common to hear the difference tone between two > strings when tuning a 5th. The difference tone is an octave below the lower > string of the 5th. There are also summation tones which are a 10th above > the lower note of a 5th. Obviously when you add the frequencies of A-440 > and E-660, you get C#-1100 (we're talking pure intervals here, not > tempered). When you subtract 440 from 660, you get 220 > If I remember correctly, Wm. Braid White mentions this phenomena as well as > the Ellis translation of Helmholtz. > > Now to the other subject of single strings exhibiting a difference of pitch > from three strings which are tuned identically. In my studies, I found > that this difference exhibits itself more in the 5th and early 6th > octave on the piano and not as much elsewhere. I have not found 1 and 2 > cent variances as some have claimed. What are your findings? I find > greater differences between the pitches of the prompt sound and the > later decay sound (the TuneLab shows this quite clearly). It is easy to > confuse these two sources. > > Jim Coleman, Sr.
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