Only right channel is recording

Hello. When recording sound with Audacity 2.0.2(also with 2.0.1) on Debian wheezy 32bit only right channel is recording. What can be a reason for that?

My guess is that you are recoding something that is plugged into a mono microphone socket.
If that is the case, set Audacity to record “1 channel (mono)” and the sound will come out of both speakers.

Well, I thought also so, but it’s not so. Microphone is inserted to a front panel output of a soundcard. And a day ago when I tried to record the levels were the same … but today they are not. And such a behavior with any record software(Audacity, Ardour, gnome-recorder…). I start to think that it is because of some bug in alsa or pulseaudio or both of them.
That’s crap.

Is it a mono microphone or a stereo microphone? (most microphones are mono).

Seems like mono. It’s like it (one minijack for microphone and another for phones) just different model.

In that case, set the number of channels to “1 (mono)” in the Device Toolbar.
I don’t know why it appeared to record in stereo previously. Could you perhaps have had it plugged into a different socket?

No, I haven’t pluggedi it into a different socket. Here is when previous record on Linux and here is when recording on Windows 7 (steadily since records).
Records in stereo.

Does it matter? All you were doing before was recording in mono and duplicating the mono to left and right, correct?


Yea, I’ve got it. But I just was wonder why before it was recorded automatically to stareo and now not, so I have to duplicate it manually. I booted into Debian 6 live and it records automatically into stereo(dual mono). Maybe something changed in alsa in Debian 7…

Why do you need to duplicate it? Why not leave it as a single mono track? A “stereo” track that is a “duplicated mono track” sounds exactly the same as a single mono track but takes up more space, both on screen and on disk.

Well, if this is so - I’ll know for the future. But why then people make stereo recordings? Maybe mono is good for voice and stereo is good for musical instruments?

Recording in stereo is good whenever you are recording a stereo input, for example if you are using a pair of microphones or recording a stereo broadcast or recording a stereo mix from a mixing desk.
If you are recording a mono input, for example a single microphone or one plugged in instrument, then mono tracks are generally preferable.

The funny thing is that now it again records(Debian wheezy) by default in stereo mode. I wonder why? Maybe because of the new updates, maybe something else.

It’s not actually recording “stereo” if you are recording from one mono microphone, though it may record that mono signal into both left and left channels if you set Audacity to record 2 channels. Whether or not it does this depends on how the system handles the signal before it gets to Audacity. Between your microphone and Audacity there is the sound card hardware, the sound card drivers (ALSA) and the rest of the sound system (in that image you are using “Pulse”). Changes / updates to any of these components could change whether mono signals are treated as one channel (with the other channel silent) or as 2 identical channels.

Actually people usually record in mono and then create a stereo mix in the mastering studio placing the instruments and voices acroos the stereo “sound stage”.

People make these stereo mixes to create an aural “picture” with the peformers spread out across the virtual “stage”. If they do it badly then the results are not always better than mono - a good example being the Beatles ealy stereo releases.

Just occasionally people will make a stereo recording of a live performance with a single stereo mike.


Yes, I meant that mono signal is automatically treated as 2 identical channels.