[78-L] audio software

[Graham Newton]

Jeff Lichtman wrote:

> I use it to figure out the correct playback speed for a record - not 
> to correct pitch variations within a record. I use the spectrum 
> analyzer to get the frequencies of notes in the recording and figure 
> out how much it would have to speed up or slow down for each note to 
> be on pitch. I then take the average of the speed changes and use 
> that to figure out the correct playback speed.

One of the perplexing problems of restoration of "78" rpm discs is "pitching" 
or setting the speed of a turntable so the music is not being played between 
notes.  They weren't always recorded at or even near the implied speed!

A pitch-pipe or quartz tone standard works well as a reference, but confusion 
still reigns... should you adjust the speed UP to get to the next note, or 
adjust the speed DOWN to go to the previous note?

Having a music score to refer to would be a big help, but even that might have 
been subject to alteration by the musicians at the time the recording was made. 
  Knowledge of the style of music and what keys it is *usually* played in is a 
hint to what it should be.

Having some 60 Hz hum (50 Hz in Europe and some other countries) in the 
recording is one of the easiest ways to determine what the actual speed should be.




... Graham Newton

-- 
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