[Scott Dorsey]

Richard Kuschel wrote:

I never heard of this rule of thumb before, but--

I get it. So 120 X 5000 equals 600,000 and if a telephone is
200Hz-3kHz it still = 600,000

Right. There's actually a paper on the subject from the BSTJ some time in
the 1930s. I will see if I can find a citation on it. But the notion is
that for the response to be subjectively "balanced," whatever is lost on
the top needs to be balanced with a corresponding loss on the bottom and
vice-versa. Note that once you get beyond 10KC or so, this becomes less
and less the case, and the original paper was entirely about voice reproduction.
Still it's a good rule of thumb.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."