Mono input to Stereo output

I’m using Windows 7 (all updates) and Audacity 2.0.5. I want to make a stereo voice “track” as the intro track for a CD of a family reunion. The balance of the reunion was recorded in stereo (clean recording, no problems, as a test, I can make the desired CD from the “raw” recording). I would also like to add a voice track introduction as track #1 and have successfully done so if I leave the intro as a “mono” recording. No problem, My preference, however, is to convert the existing mono voice recording “intro” into stereo for playback purposes, so that it plays back on both channels. The obvious approach seemed to be to duplicate the recorded single channel to the second channel. I’ve tried copying (“select all”) and pasting the mono recording of the “left” channel to the “right” channel. It works but I get a minor but very annoying echo effect. I assume my problem is that I can’t precisely place the copied channel at the same starting point as the original mono channel.
Or, am I doing something else wrong? Suggestions?
I can manipulate the existing mono recording or, alternatively, if a better approach, I could set up Audacity differently and re-record the “intro” to capture two channels (from the mono source) in the primary Audacity recording - it is a brief intro, so not a problem to re-record the intro using different settings if that’s the best approach to generate a two channel playback.
thank you for your time and any suggestions,

Select the mono track by clicking just above the MUTE button. Edit > Duplicate.
Drop-Down Arrow to the left of the top track > Make Stereo Track.

I like doing it that way, too.

You can also probably change the voice track to “real” MONO with the left drop-down and that should work, too. It’s probably LEFT now, correct? That’s why it’s only playing on the left of the show.


If the mono track actually says “Mono” above the Mute/Solo buttons there is no need to make it stereo as long as you already have a stereo track. It will already play through left and right channels and be mixed into both channels when you export.


The poster suggests, obliquely, that the voice track only plays on one side or there is some other problem with it.

I’m not sure why copy and paste didn’t work. That’s troubling. If you use the hot keys for Home, Copy, etc, etc, that should work.

I know of no way to force a mono microphone to record in stereo without resorting to analog technologies. Crossing a stereo recording with a mono microphone by accident is a good way to kill a performance. To my knowledge, the only way you can cross mono/stereo is with certain built-in microphones or built-in connections that are designed to do that, and some of those don’t go both ways.


Koz, et. al.,
Thanks for your comments. I did not “force” a stereo mic to record only a single channel in mono - I used a mono mic (made by Akai, non-directional, 50k impedance.)

What I now realize, based on chasing approaches after getting the first posted suggestion, was that I had Audacity set “as usual” for me, for my typical use, so I had it set for recording in stereo, yet used the mono mic. So, I got “input” on only a single channel (left) but the second channel was “running”, so to speak, ready to record. I suspect that dead space on the opposite (right) channel has something to do with marker or other software “insertion” that may have been made on the “empty” channel. And, as are you, I am also confused as to why a glorified “copy and paste” approach (using all Audacity pull down’s/menu choices to implement the approach) doesn’t work - or hasn’t as yet.

I’m still fiddling with it and I’m confident I’ll get there. Suggestions such as the one of the first reply to my post have been very helpful, as is yours, in insuring I’m aware of both “where I am” (i.e., noticing the stereo default set-up) and also in checking additional approaches to accomplish the “copy and paste” approach, as there are various Audacity menu entry points, of course.

Again, thanks for the thoughts and when I am successful, I’ll post the 'how", and what worked.


Apologies - I just read your second post you made, responded to it and didn’t realize you had also made the initial comments - each of which are helpful.

thanks again for taking the time to comment,

Dueling posts. I bet I can post faster than you can…

That duplicate and change the track designation thing should work. Let us know where you get stuck.


Yes, but for the benefit of others reading this, the original post could be read that it was a mono track. We now know it was in fact recorded in stereo left channel only (but I presume was subsequently split to left and right or split to two mono tracks).

It needed to be clarified that if the left channel had been made mono there was no need to duplicate it, given there was already a stereo track.