Clemens Ladisch writes > | I can hear a feedbock from the headset's microphone onto the headset > | speaker > > > It makes no difference in my tests. > > But does it come from the computer? Does it vanish if you unplug the > mic jack? The white noise that I head when Mic Boost is up and Mic is up does not go away when I unplug the microphone jack of the external microphone. It disappears when I mute Mic. Muting Mic and unplugging But the feedback (most noticable from scraping a bit on the microphone) goes away. > > > alias testsound='arecord -r 20000 -d 2 > /tmp/a.waf ; aplay /tmp/a.waf' > > Please try with two channels (-c 2). Does not seem to make a difference. > > I notice no difference whether external microphone is plugged in > > or out. I therefore think that the external microphone does not work. > > When mic is high and mic boost is up, I hear a white noise on > > the headset and a faint small feedback from the external microphone > > So it _does_ work. It does not record, just feedback. > >> Does "Mic Boost" have any effect? > > > > It goes up during skype sessions. My correspondants say it is > > better when it is down. > > What's the difference? I made a short recording, http://wotan.liu.edu/home/krichel/tmp/mic_boost.waf to demonstrate the effect of Mic Boost at 100, 51, 20 and 0. > In theory, the data you capture should be the same that is sent out > by Skype. Sure. Another hint: there appears to be two built-in microphones on this laptop. One is on top of the lid, next to the webcam. The other is on the chassis, left, close to screen and on switch. Scatching on them, during a recording, I have not been able to find out which one is the one that is working. Now coving the internal microphone in the chassis, I can still hear my test recording when the external microphone is plugged in but I can hardly hear it when the extrenal microphone is plugged out. So contrary to what I claimed the external microphone is working, it is just that the internal microphone can not be switched off because ALSA does not give me the option, and when the external mircophone is plugged off the internal sets in to create the impression that the external is not working, since the recordings are similar. I spent some time fiddling with sound settings that hopefully avoid the microphone boost going up in Skype. Thank you so much for your support Clemens. If you make it to NYC, I will be happy to have you as my guest. Cheers, Thomas Krichel http://openlib.org/home/krichel http://authorprofile.org/pkr1 skype: thomaskrichel ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
