[Bug 16454] Re: sound still comes out of speakers when PCM volume is set to 0

kko ko69859 at uta.fi
Tue Feb 20 09:35:58 UTC 2007


Hello.

I've been wondering at the same issue on Kubuntu Dapper. Sound output is
functional when PCM _or_ master volume is set to 0. Only when _either_
one of these gets muted (from e.g. kmix), does sound output stop.

I'll attach the requested files (with the prefix "1."). "PCM_0" and
"master_0" indicate the volume is set to 0 on the indicated channel.
Here's the relevant output from 'diff':

$ diff 1.amixer.PCM_0 1.amixer.PCM_0.muted
52,53c52,53
<   Front Left: Playback 0 [0%] [on]
<   Front Right: Playback 0 [0%] [on]
---
>   Front Left: Playback 0 [0%] [off]
>   Front Right: Playback 0 [0%] [off]

diff 1.amixer.master_0 1.amixer.master_0.muted
6,7c6,7
<   Front Left: Playback 0 [0%] [on]
<   Front Right: Playback 0 [0%] [on]
---
>   Front Left: Playback 0 [0%] [off]
>   Front Right: Playback 0 [0%] [off]

PS. The volume control in alsa acts somewhat strangely. With PCM volume
at reasonable levels, the master volume slider doesn't affect the
audible volume for roughly half the way from zero upwards. Only when
above this threshold, does the audible volume change. Is there a
technical (hardware) reason for why this happens? Or is this an issue
that would warrant a separate bug report?

** Attachment added: "1.cards"
   http://librarian.launchpad.net/6478845/1.cards

-- 
sound still comes out of speakers when PCM volume is set to 0
https://launchpad.net/bugs/16454




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