I have been digitizing a batch of tapes for a university music program's
archives. Most were made in a the several campus performance spaces, and
from the sound of it and experience, the preponderance of these
recordings were made with spaced hanging cardioid microphones. While
stereo mics were also widely used, these sound like spaced mics.
Anyway...none of the tapes had tones and from time to time there is a
tape with an offset solo instrument. Remembering that we're looking for
fractions of a degree accuracy in adjusting azimuth playback, when we
see two separated mics, all bets are off.
With the speed of sound being about 1100 feet per second, we can see how
moving a mic less than a foot is the length of a complete cycle at 1 kHz.
So, this type of recording is almost impossible to accurately adjust.
While full ensembles work well with the stripchart in StereoTool, a solo
instrument or voice can show a huge azimuth error which is really an
artifact of microphone placement relative to the source.
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada 647 479 2800
Quality tape transfers -- even from hard-to-play tapes.