Audacity Forum

Hello:

I am a newbie to home digital recording, and I am trying to record acoustic instruments, from a Samson CO1U, USB microphone into a 4 year-old MacBook running OSX 10.6.8.

For some reason, it seems that Audacity defaults the recording to the Left channel only.

I followed the other directions about setting "stereo recording" etc. in all the various preferences and midi utilities...It seems I have just messed up some setting somewhere...

...any thoughts?

Many thanks!

PS - I did read around the "stereo splitting" post-recording work-around, but I'd just rather get it right the first time!

The Samson CO1U USB microphone is a mono device. It only produces one (mono) channel of sound. Set Audacity to record "1 channel (mono)" in "Edit menu > Preferences > Devices" and you will get a mono recording that plays through both left and right speakers/headphones.

Hi Steve:

Thank you for your helpful suggestion.

I did the change you suggested in the "preferences" menu under "Audacity" - and it didn't change the fact that the monitor only showed recording from the Left channel. I notice now, after re-reading your suggestion that you suggested changing something under the "edit" menu - was this a typo on your part? Or have I altered the wrong "preferences" (I don't see a preferences option under "edit" right now, but I'm not in recording mode..)

- I'm imagining that the second possibility is that if I have set Audacity up successfully to record mono, it does not really matter if the Monitor looks like it is only recording through one channel, as the actual track has only a single channel too. Am I right? Or should I keep trying to tweak it?

Thanks again!

I think you probably have it set up correctly, but just in case I'll post a more detailed description:

To open the Audacity preferences, Click on the "Edit" menu at the top of the main Audacity window, then select "Preferences" from the drop down menu.
This will open up the Audacity "Preferences" window.

In the Audacity "Preferences" window, select "Devices" in the left hand section of the window, and in the right hand section you will see an option for "Channels:"
It should look something like this (though the other settings will be different because I'm using Linux):
When you record, you will see only the left channel moving in the (red) recording meter. That is normal because you are only recording a single (mono) audio channel.
When you play back the recording you will see both left and right channels moving in the (green) playback meter because a mono track will play back through both left and right channels.

It's a typo. In Mac, that's Audacity > Preferences > Devices. It's not under the Edit menu.

Koz

I thought there was a way to force the machine to record a two-track mono signal, but I can't find it now.

There are ways of mixing a mono microphone with stereo music, but I think it's too confusing, so I go through the Edit > Duplicate Track and then Make Stereo from the left-hand menu items. This puts everything in stereo on the timeline.

But by itself, a mono track is perfectly valid and will play through both stereo speakers. It's half the size of a stereo track, too.

Koz

kozikowski wrote:It's a typo. In Mac, that's Audacity > Preferences > Devices. It's not under the Edit menu.

Thanks Koz. As we're talking about a Mac I should have checked the manual

kozikowski wrote:I thought there was a way to force the machine to record a two-track mono signal, but I can't find it now.

On computers that are not Macs it depends on the audio device driver. In most cases a mono device, when set to record to a stereo track, will record only to the left channel leaving the right channel as silence. In a small minority of cases a mono device, when set to record to a stereo track, will record the same mono signal to both channels. I'm not aware of any setting in any version of Audacity that affects this. I guess that on a Mac there may be a setting in the Mac configuration.

kozikowski wrote:There are ways of mixing a mono microphone with stereo music, but I think it's too confusing,

It's pretty simple really.
Whether a mono or stereo track, there is a "Pan" slider on the left side of the track. Moving this slider left/right does not change the actual data in the track in any way. What it does is to change how it is sent to the main stereo output (as shown in the Playback meter).

For a stereo track, pushing the Pan slider to the left will reduce the playback volume of the right track channel (making the sound appear to come from left of centre). Moving the Pan slider to the right will reduce the playback level of the left track channel (making the sound appear to come from right of centre). When set to centre both the left and right track channels will play at full volume to their relative playback channel.

For a mono track, pushing the Pan slider to the left will reduce the playback level out of the right playback channel (making the sound appear to come from left of centre). Moving the Pan slider to the right will reduce the playback level out of the left playback channel (making the sound appear to come from right of centre). When set to centre the mono track will play back equally to both left and right playback channels (making it sound central in the mix).

When mono or stereo tracks are mixed down they will produce an output that is the same as the playback mix. Basically it is "pretty simple" because you don't really need to know or understand how it does it. When you Export your final mix, the file produced will sound the same as when you play the unmixed Audacity Project.

There are a few situations when a 2 channel (stereo) track for a mono sound is required, but this is fairly uncommon. One example could be that some old CD burners require stereo (2 channel) files. In such cases, the procedure that you describe (duplicate the track and then join them as a stereo track) is an easy way to produce the 2 channel track. Most modern CD burners do not have this constraint.

Touching that pan control on a mono show cause a number of undesirable things to happen:

-- It causes the sound meters and the time line to not match.

-- It cause the speakers and the time line to not match.

-- It causes the exported show not to match the timeline.

-- It causes the exported show, when re-imported to the same project to wildly not match the original show.

-- It causes what looks like a mono show in what is without question a mono Project to export a stereo show.

-- Worse yet, it's possible to nudge the pan control just enough to cause the error and yet not make it obvious in any way what the error is.

Sorry. I'm not a fan. This behavior skates dangerously close to the "B" word.

The system should ask you if you want a stereo show after all and then switch the timeline to match if you say yes. Alternatively, I would expect a pan control in a mono show to do nothing.

Under no circumstances should all these changes happen behind the scenes.

Koz

I know we don't usually like the mixing desk analogy, but if you have a microphone (mono) plugged into a mixing desk and move the channel pan pot to the left, then the (desired) result is that the microphone signal moves to the left in the stereo field. That's exactly what is happening when you move the pan slider on a mono track.

What happens when you're playing your Jimmy Johnson "South" recording (mono) on your stereo and you move the "balance" knob to the left? The sound from your speakers "pans" to the left (as expected). Again, this is same as what is happening when you move the pan slider on a mono track.

Lets say that someone has recorded 4 tracks - each track has been recorded (one at a time) with a (mono) microphone. They have recorded a string quartet. All instruments will play from dead centre in the mix, but string quartet musicians rarely all sit on each others knees. So you want to pan the 1st Violin 25% left, 2nd Violin 10% left, Viola 10% right, 'Cello 25% right. To do this, all you need to do is move the pan sliders by these amounts. If you had to duplicate each track then adjust the levels of each track to produce the required shifts in the stereo field, that would be an incredibly cumbersome way to produce the desired result.

kozikowski wrote:-- It causes the exported show not to match the timeline.

That should not happen. if it does, it's a bug.
How does the timeline come into this question? It shouldn't. Can you give steps to reproduce.

kozikowski wrote:-- It causes what looks like a mono show in what is without question a mono Project to export a stereo show.

It would probably help if there was some visual indication that the show is now stereo - oh, but there already is - the left and right meters show different levels. Do you want a more in-your-face indication of a possible user error? It would need to be turn-offable for people that use the pan slider as intended.

kozikowski wrote:The system should ask you if you want a stereo show after all

I think that the idea of "Export Mono" is a good one. It would certainly be of benefit to people producing (mono) Podcasts. If Exporting as mono in a compressed audio format the user could be alerted to the bit rate and asked if they want to reduce it by half.

kozikowski wrote:all and then switch the timeline to match if you say yes

Again, what does this have to do with the TimeLine?

kozikowski wrote:Under no circumstances should all these changes happen behind the scenes.

In what way is it "behind the scenes"? There's a control, and if you use it, something happens. Would you say the the volume slider acts behind the scenes? How about the balance knob on your stereo, does that act behind the scenes? or the steering wheel in your car?