15 Aug
2006
15 Aug
'06
9:36 p.m.
Dominique Michel wrote:
Le Tue, 15 Aug 2006 12:01:11 -0400,
Lee Revell <rlrevell(a)joe-job.com> a écrit :
ALSA is starting to support "dB Gain" indications for mixer controls. It
currently supports Creative Audigy cards and USB sound cards. Support
for other sound cards will follow in time.
So, at least people will know where the 0dB gain point is for the mic
and line in.
James
On Tue, 2006-08-15 at 16:51 +0100, Dan Mills
wrote:
It is a good news.
With jack, mixers as jackeq or jackmix are already using db scales.
Dominique This is dependent on the microphone, preamp and
sound
card in use, or for the output case, the soundcard,
power amp gain and speaker sensitivity (plus room
effects).
You need to ensure that 120dbSPL at the transducer
does not clip either hhe mic, preamp or soundcard and
then find out what sample value this gives with your
hardware. Calibrate that point as 120dbSPL, then as
long as all your hardware is linear the rest of the
thing will just work.
FWIW, there is some work going on in ALSA to make the
drivers use dB
units for the mixer, rather than arbitrary scales. But of course this
will only work for devices for which the developers have the full
hardware specs.
Lee