Strange problem with exporting mono files as stereo


I work on an audio drama and am seeing an odd problem as I’m doing post-production on the show. I’m sure it hasn’t always been there, but it has been popping up a lot lately: Basically, a scene of the show consists of several tracks that are recorded in mono. Once outtakes are removed, sound effects added, etc, I set each track to be either left channel, panned 30% right or right channel, panned 30% left and export it all to a single mp3. This used to result in a nicely balanced scene. However, now when I do it the tracks end up 100% left or right, regardless of the panning. Is this a bug in audacity or am I just not getting something? One possible other factor: I honestly don’t remember if this is the case with the files I’m working on now, but in a couple of cases, for reasons I’m unsure of, the raw recordings I was handed were stereo instead of mono. Perhaps stupidly, instead of squishing them down into one track, I simply split the tracks and deleted one of them, then set it to mono. My understanding of the technical bits behind this is not great (as you can probably tell), but I’m guessing this could explain the issue I’m having. If that’s it, can someone suggest a workaround? If not, what else might be going on? It would mean a whole lot of work to have to start over. :frowning:


The proof of this might be to take about a minute of this material and convert it to stereo, export it and pretend you’re starting over with a minute-long show. (don’t Save anything. Save is magic in Audacity and not always in a good way.)

Audacity doesn’t really delete anything when you press Delete. Editing is just the program writing an Edit Decision List to tell the show what your future intentions are. Nothing happens to the original files. Some extra effect production files may get written if you have a complicated show, but your original client supplied sound files are still there and they’re still in stereo. If the production changed the deliverable format, then all sorts of messy things can happen. Mono files, no matter where in the EDL they appear, do not have a Left and a Right.


Well, the original files are generally mono, not stereo. The trick is that I want to go from that to each track being on either the left or the right channel of the finished stereo file, but since voices sound really grating when they’re only in one ear, I want the left tracks to show up a little on the right and the right tracks to show up a little on the left. I could swear that once upon a time this was just a matter of clicking the down arrow on one of the mono tracks and selecting, say, ‘Left Channel’, then dragging the pan slider three steps to the right, but obviously that’s not working right now and I’m beginning to wonder if it ever could have.

Could you elaborate on what you mean by “convert it to stereo”? I’ve tried several techniques, including copying each track and selecting “make stereo track” to combine the copies. If I do that, I can do some panning, but I have to pan more like 80% in order to get the balance I’m going for. Is that what you mean to do? Is there a simpler way? And have I just really not been paying attention or is there any way this could have been working with mono files only, as I describe above?

Thanks again for your help.

On a completely wild guess, is Audacity still the normal 2 channel stereo show you started out with? I’ve had one install of Audacity change without my help. Audacity went nuthouse on me and it took a while to catch up. “Wait, I didn’t set it for four channels…”

Preferences > Audio I/O > Recording > Channels.


That was a great suggestion, but alas it is set to two-channel stereo.

…can I take from these suggestions that I’m right in thinking that switching a mono track to left or right and then panning should result in a track that plays mostly in one ear, but also a little in the other?

Perhaps this will help. here is an example of the problem we’re having. It’s a 320kbps, mono mp3. Try changing it to a Left track panned 30% right and you’ll still see (or at least I still see) it playing 100% on the left. I’ve tried everything I can think of to fix this, including duplicating the track, creating a stereo track from that, and then running Stereo To Mono on it. I still end up with a track that can either be 100% left or 100% right, but is not affected by the panning slider. This poses a huge problem for us and has basically stalled my ability to do work on the show. :frowning: If anyone has any insight into what’s going on and how to fix it, I would really appreciate it!


No, that’s not correct.
If you set a mono track to “Left channel” then it will ONLY play through the left channel. Adjusting the “Pan” slider will affect how much comes through the left channel, but NO sound will come from the right channel.

The pan slider will work as you expect on either a mono or stereo track.