From: Jim Peters (jim_at_uazu.net)
Date: 2002-01-28 12:12:15
arethereanytagsleft wrote:
> > A quick test confirms this, more or less -- from line-out on one
> > PC to line-in on my laptop gives the following amplitudes:
> >
> > 100Hz 32000
> > 10Hz 10000
> > 8Hz 9000
> > 4Hz 6000
> > 2Hz 2000
> > 1Hz 1000
>
> Are you sure you haven't ommitted a k (ie, should your numbers be
> khz ?)
I'd be doing very well to get 100kHz with that response ! No, they
are definitely Hz (and I could hear the 100Hz sine tone through the
sound card mixer if you need any more convincing).
But look at the fall-off. Definitely this isn't a flat response. You
might expect 20Hz to give 32000, but things are falling off rapidly
after that. At 1Hz it's down to 3%. This is terrible, and as
expected, but it would be good enough for rough testing. I can
compensate for it a little.
> Sound cards use capacitors in the signal path, so any DC level is
> removed. This means also that there is a lower frequency limit
> because of the highpass characteristic of the capacitor in line. The
> lower cutoff frequency is card dependent. AFAIK most soundcards
> cannot detect frequencies <= c. 20Hz
Well, try it and you'll find out for sure.
Jim
-- Jim Peters (_)/=\~/_(_) Uazú (_) /=\ ~/_ (_) jim@ (_) /=\ ~/_ (_) www. uazu.net (_) ____ /=\ ____ ~/_ ____ (_) uazu.net
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:37 BST