This is an older Dell system whose on-board sound chip
is a CS4237 and it has worked well until I replaced the boot
drive with a flash drive. This makes the system faster but audio
now has a problem that I would sure like to correct as it is
annoying to say the least.
I began noticing it when listening to mixtures of voice
and music so I played a steady 400-HZ tone for several seconds
and listened to it.
Every 2 to 5 seconds, the tone takes a very small hit.
Sometimes, the hit is in the form of a small tick as if the
samples sped up and other times, the tone takes a hit that
sounds like the samples slowed for a tiny fraction of a second.
I thought it might be related to kjournald writing to
the flash drive so I found a command one can place in to
/etc/sysctl.conf that sets the write schedule for updating the
journals. This time, I set it to a minute to see if anything
changed. No change at all and the hits just kept on coming.
I also temporarily took out the commands in
/etc/modprobe.d/alsa-base.conf that determine the order of the
sound cards and that had no effect.
This system actually has always had a tendency to do
this very slightly but the glitches got worse after the new hard
drive.
Except for that, the CS4237 has always made good recordings and
playback. The little hits are now big enough, however, to be
audible during normal speech.
Another thing I tried was to change the nice number of
either mplayer or aplayer while it was playing the tone to see
if the problem got better or worse. No change at all.
It sounds as if it might be a buffer issue since, as I
understand it, the sampling rate is clocked in the card and the
buffer should have enough capacity to not run out as long as
playing or recording is being done.
Before I changed the boot drive, I could sometimes
damage a recording by lots of file activity on the second IDE
drive on the same controller as the boot drive.
The glitches are not audible at low sample speeds such
as 8000 Hertz such as communications-grade audio but are most
pronounced during 44.1 KHZ sampling.
Any ideas on anything else to tweak?
Thanks for any constructive ideas.
Martin McCormick
--
To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive:
https://lists.debian.org/20140918023227.99a8722...@server1.shellworld.net
