Poor sound quality with snd_via8233

[Oliver Fromme]

Ariff Abdullah <ariff at freebsd.org> wrote:
 > Niklas Sorensson <nik at cs.chalmers.se> wrote:
 > > apa# /usr/sbin/mixer
 > > Mixer vol      is currently set to 100:100
 > > Mixer pcm      is currently set to 100:100
 > > Mixer line     is currently set to 100:100
 > > Mixer mic      is currently set to 100:100
 > > Mixer cd       is currently set to 100:100
 > > Mixer rec      is currently set to 100:100
 > > Mixer igain    is currently set to 100:100
 > > Mixer ogain    is currently set to  10:10
 > > Mixer line1    is currently set to  75:75
 > > Mixer phin     is currently set to   0:0
 > > Mixer phout    is currently set to   0:0
 > > Recording source: mic
 > > 
 > Reduce those "100" to "85", or less. You're overdriving it too much,
 > hence, the constant distortion. If you have amplified speaker, use the
 > volume knob there.

In fact, I would recommend to set _all_ of them to zero,
except for those that you really need (probably just "vol"
and "pcm").  Otherwise your soundcard might pick up some
noise from non-connected analog ports (e.g. line or mic),
amplify it in the mixer and reduce the overall signal-to-
noise ratio.

 > Report (and partially from my experiences) indicate that using
 > SCHED_ULE can give better audio/multimedia performance. Perhaps you
 > want to give it a try.

While we're on the topic ...  I'd like to say a BIG THANKS
to all people working on FreeBSD, particularly the multi-
media stuff (sound drivers, AGP, DRI/DRM), the scheduler,
VM system and what-not ...

Yesterday I burned a CD-R while a lengthy port was compiling
in the background, _and_ I watched a video fullscreen at the
same time.  No sound skipping or any problems.  The CD image,
the port and the video were all stored on the same HD.  That
was on a Centrino 1.6 GHz notebook (ICH6 sound hardware, i915
graphics), running RELENG_6, with the standard BSD scheduler.
And yes, the CD-R that I've burnt has no errors.  :-)

Best regards
   Oliver

-- 
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd
Any opinions expressed in this message may be personal to the author
and may not necessarily reflect the opinions of secnetix in any way.

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