[pulseaudio-discuss] Awful Quality in Sound

[Colin Guthrie]

Rémi Cardona wrote:
> Richi Plana a écrit :
>>> Is there any way to test what is causing this and if it is PulseAudio?
>>> Is there a simple way to override PA and play audio via ALSA
>>> snd-hda-intel drivers?
>> Alright, it MAY not be PA. I tried playing music from a virtual console
>> using oss as the output device and it still sounded horrible.
>>
>> One thing I did discover, however, was that when I turned up the Master
>> volume setting and minimized the PCM volume setting, the audio quality
>> improved tremendously. There seems to be some kind of attenuation going
>> on when PCM controls are used. Why that is, I've no idea.
> 
> Try to use alsamixer to set the PCM level to 0 dB or bellow. On my
> laptop, this level is around the value of 75%.
> 
> My take on this is that the PCM control allows to amplify the signal
> beyond reasonable levels (ie above 0 dB).

If pulse is the !default in alsa configuration then remember to use -c 0
argument to alsamixer to get the mixer for the hw rather than the pulse
plugin's mixer.

Also as pulse 0.9.7+ suspends the device (e.g. lets other apps use it
directly) you can just use e.g. mplayer -ao alsa:device=hw=0 file.wav

Col