Problems capturing audio with Intel ICH5...

Many thanks, I'll give it a try and let you know if things get better.

Best regards.

Florian Kulzer wrote:
> On Sat, Sep 29, 2007 at 11:59:04 +0200, Andrea Giuliano wrote:
>> Florian Kulzer wrote:
>>> On Wed, Sep 26, 2007 at 22:51:30 +0200, Andrea Giuliano wrote:
>>> Maybe gnome-mixer does not give you access to the relevant capture
>>> controls.
>> I guess I tried every single control, they're even too many, but this
>> could a possibility: a control that doesn't affect playback during
>> recording, but affects the volume of the recording itself. But which?
>>>> Alsa seems correctly configured (at least, sudo alsaconf gives no error).
>>> Please post the output of:
>>> lsmod | egrep 'snd|intel8x0'
>>> amixer | egrep -i '^( .*capture|[^ ])'
>> Here they are. Please note that I have both cards installed, but I put on
>> the Ensoniq after I got the audio problem, so I'm almost sure the Ensoniq
>> has no relevance, at present.
>
> I agree, let's ignore the presence of the Ensoniq card for now.
>
> [ snip: list of loaded snd-modules looks OK to me ]
>
>> Simple mixer control 'Master',0
>> Simple mixer control 'PCM',0
>> Simple mixer control 'Surround',0
>> Simple mixer control 'Surround Jack Mode',0
>> Simple mixer control 'Center',0
>> Simple mixer control 'LFE',0
>> Simple mixer control 'Line',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Playback 25 [81%] [on] Capture [off]
>> Front Right: Playback 25 [81%] [on] Capture [off]
>> Simple mixer control 'CD',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Playback 0 [0%] [off] Capture [off]
>> Front Right: Playback 0 [0%] [off] Capture [off]
>> Simple mixer control 'Mic',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Playback 25 [81%] [off] Capture [on]
>> Front Right: Playback 25 [81%] [off] Capture [on]
>
> You probably already tried to reduce the Playback level for the mic (to
> make sure it is not some weird feedback effect).
>
>> Simple mixer control 'Mic Boost (+20dB)',0
>
> Check the full output of amixer for the Mic Boost settings. I would put
> it at 1.00 dB or even 0.00 dB for a start.
>
>> Simple mixer control 'Mic Select',0
>> Simple mixer control 'Video',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Capture [off]
>> Front Right: Capture [off]
>> Simple mixer control 'Phone',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Capture [off]
>> Front Right: Capture [off]
>> Simple mixer control 'IEC958',0
>> Capture channels: Mono
>> Mono: Playback [off] Capture [off]
>> Simple mixer control 'IEC958 Capture Monitor',0
>> Simple mixer control 'IEC958 Capture Valid',0
>> Simple mixer control 'IEC958 Playback AC97-SPSA',0
>> Capture channels: Mono
>> Simple mixer control 'IEC958 Playback Source',0
>> Simple mixer control 'PC Speaker',0
>> Simple mixer control 'Aux',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Playback 7 [23%] [on] Capture [off]
>> Front Right: Playback 7 [23%] [on] Capture [off]
>> Simple mixer control 'Mono Output Select',0
>> Simple mixer control 'Capture',0
>> Capture channels: Front Left - Front Right
>> Limits: Capture 0 - 15
>> Front Left: Capture 15 [100%] [on]
>> Front Right: Capture 15 [100%] [on]
>> Simple mixer control 'Mix',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Capture [off]
>> Front Right: Capture [off]
>> Simple mixer control 'Mix Mono',0
>> Capture exclusive group: 0
>> Capture channels: Front Left - Front Right
>> Front Left: Capture [off]
>> Front Right: Capture [off]
>> Simple mixer control 'Channel Mode',0
>> Simple mixer control 'DAC Clock Source',0
>> Simple mixer control 'External Amplifier',0
>
> If you cannot improve the recording quality by reducing the Mic Boost
> then you could try to successively turn all capture controls to zero
> until you find the one that causes the distorting amplification. I
> recommend using "alsamixer" for this; it has a curses-based interface
> which gives you a good overview of the playback and capture controls.
> You can switch between the two groups of controls by pressing the TAB
> key; use CURSOR LEFT/RIGHT to select a control, CURSOR UP/DOWN to change
> volume/amplification, and SPACE to toggle capture.
>
> The names and the interaction of the capture channels are not the same
> for all cards, unfortunately. Therefore you are left with trial and
> error, but I am pretty sure that one of them will allow you reduce the
> amplification to a reasonable value. The names of the controls are
> sometimes confusing or at least not really helpful; for example, my
> Intel ICH8 card has a control called "Digital" which determines the
> amplification of the recordings. If I set it to its maximum value of 30
> dB then I get the same kind of problems that you described in your
> earlier mail.
>

--
Andrea

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