On 01/15/2014 12:12 PM, Bill Unruh wrote: > On Wed, 15 Jan 2014, David Vincent-Jones wrote: > >> >> Takashi Iwai <tiwai <at> suse.de> writes: >> >>>> David Vincent-Jones wrote: >>>>> Reference: >>>>> http://www.alsa-project.org/db/?f=b5c0d636c3870da14ab5f4e4c6f5f64d7c906507 >>>>> >> >>> If this still doesn't work, it can be rather the way of testing. >>> This digital mic might be a PDM unit with the inverted signal in one >>> channel. Try to record a stereo stream, e.g. >>> >>> arecord -Dhw -fdat -vv foo.wav >>> >>> Or, try to pass model=inv-dmic. If this works, we can cook up a >>> correct patch. >>> >>> Takashi >>> >>> >> The arecord produced only 'white-noise' but no microphone input >> whatsoever. > > If you really ran the above command just as stated, then the "inverted > mic" > explanation is not the right one. > > One thing you always need to do is to make sure that the volume in > alsa is set > properly for the input. Eg, I was driving myself mad because the sound > was > very noisy (but there was a signal). I was almost ready to send the > computer > back under warrenty. I should have known better in that it > took me a while to look at the alsamixer and discover that the volume > slider > on the input was way down. I felt very silly. > >> >> Could you please advise how to pass model=inv-dmic .... and I will >> give that >> a try. One thing that I do notice is that whenever I open alsamixer, 'pulse' appears to be the default and when I switch to HDA Intel PCH the settings for the Microphone have all been disabled. Would it be helpful to temporarily remove Pulse? Can I manually edit /var/lib/alsa/asound.state to lock in values? David ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
