Problem with maximum audio volume + volume control threshold
I hope the following hasn't been asked many times before (or is blatantly obvious), I've searched the forums and couldn't find a thread which applies to my problem.
Anyway, I've got problems with volume control. To get a fairly decent volume (it's still too low for my tastes) I have to yank the slider volume to its maximum - everything is in the red regions of the alsamixer interface.
When I use the volume slider of Kmix or alsamixer from the command line to assert some more detailed control over the volume there are basically three steps: normal volume, very low volume and after approximately 10% of the slider: no volume. So the remaining 90% of the slider is dedicated to complete silence. This might be related, but I'm not sure the solution is what I need, because if I set the sliders of my mixer to 80% there's only complete silence.
This behaviour is also consistent with any external audio device (headphones, an amplifier and external speakers, or just external speakers) and consistent in both KDE 4 and GNOME - the latter I've used in the past. I'm running Debian Lenny (kernel version 2.6.26-1-686, but I had this problem with older kernel versions as well) on a MacBook Pro 15" (second gen).
I've run the module assistant to rebuild alsa. snd_hda_intel is present when running lsmod | grep intel and alsaconf correctly picks up the sound card as "Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller". Strangely enough lspci | grep audio is empty for some reason.
Does anybody know what could be wrong here?