Dave Meyers  Overkill audio inc.
[log in to unmask] wrote:

> Has anybody observed what the upper and lower frequency limits of Edison
> Diamond Discs would be?
> IE: Beyond what high/low frequency would there be little if any
> significant recoverable information?

It varies slightly with the specific recording since Edison was not a model
of consistancy.  Some discs are recorded much louder than others and some
have a decided muffled character, where others have much better clarity and
frequency response.  Most of this can be probably be attributed to the
adjustmant of the specific recording head in use on the day of the recording.

With all that said, generally, looking at a few of the discs played flat
through a spectrum display, and using CEDAR's DEQ to set up a 30th order
variable hi-pass and low-pass filter, there appears to be virtually no
program content recoverable outside of 160 Hz at the low end and 4.5 kHz
at the high end.

... Graham Newton

Audio Restoration by Graham Newton,
World class professional services applied to phonograph and tape
recordings for consumers and re-releases, featuring CEDAR processes.