Sound funnies
I am desperately trying to understand how to properly set up sound so I 
can make a recording from a microphone.
I seem to have got there but in the process I have noticed lots of 
strangeness.  Can anyone explain what is what
1) There is an application called GNOME ALSA MIXER, which replicates the 
command line tool ALSAMIXER.  The volume controls on their refers to 
SigmaTEL STAC9227 - which I believe is the chipset in use on my Intel 
on-board video.  These are all set to 100%
2) The volume control applet from the application bar starts a different 
mixer.  This is labelled HDA Intel (ALSA).  In the recording section it 
shows two controls (I have set it this way).  One appears to be the 
master volume control, the other is labelled "digital".  In order to 
record from my microphone, I have to set the volume of both the master 
control and the digital control to high.
Regardless of how I left them when I close the window, these two values 
always come up with the microphone showing muted (but the speaker volume 
not).  Unmuting them or muting them again appears to have random effects 
- sometimes it kills the sound sometimes not.
Also regardless of how I left them when I close the window, when I open 
it again the master volume is on full, the digial volume is on nothing. 
 That is until I adjust just one side of the volume.  After that it 
appears to be remembering it again.
However - it seems random as to whether I can record sound when I come 
back later.  I can make it be OK by jiggling things - but not by just 
knowing they are set right and I can leave them.
The most important thing to understand it what is this "digitial" 
channel.  Following that, is there any other controller for it that 
might be a bit more stable.
I suspect Gstreamer is an influence here - as maybe pulse audio - but 
apart from knowing these to names as buzzwords, I don't really 
understand what they do and how they sit in the path between the alsa 
sound drivers and Audacity (which is what I am using to record the sound).
I really just want a stable environment it which to work - although to 
be fair I am running Debian Unstable - which of course is a tautology.
--
Alan Chandler
http://www.chandlerfamily.org.uk
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