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> Even people who hear well, as I understand it, rarely hear 20K. So,
the question is, why should a preamp be called on to amplify
frequencies above 20 K if nobody can hear it? I frequently see
references to magnitudes above 20K; I'm guessing this is purely techno
babble.
Max,
An interesting point. When my son was in his early teens, he could
hear 21kHz. When I was working, my ears rolled off between 15 and 16
KHz, and at 72, I brag about still hearing a bit up to 13.5kHz.
(Rodent squeaks) However, on general recordings I can hear when
frequencies at the top end are filtered out.
I reckon what we lose is the phase response, and if I sample at
Message: 22.
Subject: 05ks/s, I can clearly hear the difference. I think we need these
high frequencies to maintain the HF phase and transients.
Another danger with limited frequency responses is cross-modulation,
which can be high at the limits of the frequency specs. I may not he
able to hear 15kHz, but if there is cross-mod distortion up there
because an amplifier is close to its limits it could becomes audible
making the recording sound rough.
If you listen to the tweeter end of commercial recordings, it is often
just mush up there. I'm happy at recording at 44.1ks/s as it is CD
compatible, but a case can be made out for 48ks/s or 96ks/s for high
quality masters.
David
David Brinicombe
North Devon, UK
Cogito cogito ergo cogito sum - Ambrose Bierce
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