--- In micbuilders@..., Geoff Wood <geoff@p...> wrote:
Congratulations - you are either 10 or an exception.
I don't think so. I'm 32, and have not worked much in noisy
environments nor been at many discos when younger. I can hear 18 KHz
tones, not at faint levels, but not at insane levels either. However
there's young people out there that can hear 19 KHz tones easily. My
father is 60, and can't hear 13 KHz tones even when they are blasting
my ears.
At "insane" levels, I can hear up to 20 KHz pure
tones.
More likely you are hearing distortion products from the amp or >
drivers.
I don't think so. I have used good quality source, amp and headphones
for those tests, and none of the two first show aliasing, out-of-band
artifacts or poor IMD at high frequencies on standard measurements
(CCIF IM test tones, tone sweeps). The headphones were Sennheiser
HD580. Also, very high frequency tones are more "felt" than heard,
it's a special perception inside your head (like a blade in your
brain), that is quite disgusting. I think IM products wouldn't sound
that way. Anyway, I didn't perform the measurements when putting out
such insane levels, so it's certainly possible that the amp didn't
behave as in regular conditions, but I'm almost sure this was not an
issue, but I guess I should check it to be totally sure.
However, I can't hear a lowpass of 18.5 KHz on any complex
real-world music I've tried, at any listening level that I could
bear. The most I've been able to detect in a blind test is a
lowpass
at 18 KHz, using very special music with very loud high frequency
content, and struggling a lot.
Possibly also explained by out of band effects of the filtering.
I used a 1024-point linear phase FIR filter with more than 100 dB SNR
(Cool Edit Pro 1.2a FFT filter). This and similar test files are
available at
