On Sat, Aug 29, 2009 at 08:37:17PM +0200, peter clarke wrote:
I have
(I think) wound up all the levels to maximum in the mixer, but I still
get only -20dB even with shouting into the mic.
Where are you measuring this -20 dB? At headphones, or using software?
It's the same for all hardware (2 internal and 2
USB soundcards,
different mics), 2 different computers, 2 different versions of Ubuntu
(Heron on my desktop and Ibex on my laptop) ...
Heron 8.04 is somewhat old. Try with a Jaunty 9.04 or Karmic alpha 9.10
CD without installing. Boot from the CD and use arecord or whatever is
available. Why? There is a possibility that this problem has been
detected and fixed in a later version. Also, when these CD images boot
they will use default ALSA levels rather than the levels saved on your
system.
This started a few months ago (originally, when
everything was first
installed, it was fine) so I'm pretty confident it's an ALSA-related
software issue.
That's interesting. I suggest you hide the /var/lib/alsa/asound.state
file and ask ALSA to reset the levels to default.
sudo mv /var/lib/alsa/asound.state /var/lib/alsa/asound.state.orig
sudo alsactl restore
sudo alsactl store
The expected output will vary according to the sound devices you have,
but on a test machine here I get this from the "restore" subcommand:
alsactl: load_state:1579: Cannot open /var/lib/alsa/asound.state for reading: No such file
or directory
Unknown hardware: "ICH" "Analog Devices AD1885"
"AC97a:41445360" "" ""
Hardware is initialized using a guess method
After you have done this, check your microphone level again.
If you find it fixes the symptom, compare /var/lib/alsa/asound.state
with /var/lib/alsa/asound.state.orig to see where the differences are.
--
James Cameron
http://quozl.linux.org.au/