Re: [ARSCLIST] Dynamic-frequency Range

[Aaron Z Snyder <azs@xxxxxxxxxxxx>]

I've done a considerable amount of restoration on acoustic recordings, and,
as one might imagine, the frequency response can vary widely from label to
label and session to session. However, I can make a few generalities:

Victor and Columbia seemed to have the best low-end response -- fairly
strong down to about 120 Hz. The upper end was about 4 kHz.

Edison Diamond Disc recordings in general had very little, if anything at
all, below 200 Hz. The upper end in general petered out at about 4 kHz.
However, I've seen one acoustical Diamond Disk made in 1927 (Edison held off
until mid-to-late 1927 before going electrical) which has an upper end at an
astonishing 6 kHz!

As for most of the other labels, there doesn't seem to be an awful lot below
200 Hz or above 3 kHz. Here again, this is just a generality. Recording in
those days was more of an art than a science.

The most surprising thing that I have found is that many acoustical
recordings have recoverable bass down to as low as 40 Hz! You certainly
won't hear that if played on an acoustical reproducer, and it's doubtful
that it can be heard even on an electrical reproducer. Nonetheless, the bass
information is clearly (and sometimes not so clearly) visible in a frequency
spectrum vs. time display.

As for dynamic range, this too can vary all over the place. These recordings
are probably more influenced by the performers themselves than by the
limitations of the recording equipment. Obviously, one doesn't want a signal
so loud that it would produce blasting on the recording; yet, one doesn't
want s signal so low that it gets swamped by surface noise. Theoretically,
acoustical recordings can have a considerably wide dynamic range (the only
limiter is that mechanical extremes which the cutter can achieve), but that
wasn't necessarily a desired effect.