How do I record a mono signal to the left and right channel?

I am recording a mono cassette, spoken word – with a mono Radio Shake cassette player – to my computer, line level in – exporting a .wav file to iTunes – transferring it to my iPod Touch. Audacity records it fine but because it is mono it is only recording on the left channel. Is there some way I can have it record the mono track on both channels so I can hear it in both ears with my ear buds? I assume a mono to stereo mini plug adapter would do it, but is there some way I can change the setting in Audacity or iTunes or my computer or my iPod? I have tried changing the Stereo Input to Mono but this gives me one track that is only on the left.
I am using Audacity 2.0.1, Windows XP pro Service Pack 3, Realtek High Definition Audio board
Any help would be appreciated, Thanks
Steve Golden

Audacity > Preferences > Devices > Recording > Channels. In general, you should get Left as a mono show. It just ignores Right.


You could also post-process to mono by splitting the stereo track, discarding the empty right channel and defining the remaining left channel as mono instead of left.

Obviously I’m a newbie so I really appreciate the help.
kozikowski, Thank you, this did the trick.
PGA, Thanks this works too, but means I have to record it twice and it seems to add noise. But it is a trick I’m glad to know and will use for other things in the future.

No, you record only the once. That gives you your two-channel stereo recording with sound only in the left channel. You then take that recording and do the processing I described. It’s a technique you could use any time that you forget to do it the way Koz gave you.

Also, any time you get unwanted noise in any recording, it’s worth the time and effort to diagnose the reason why. That way, you learn what not to do if you want good, clean recordings. Koz has his “four horsemen”: the things can ruin your recordings that you must avoid. I have my two truisms:

  • you cannot turn a bad recording into a good recording - once a bad recording, always a bad recording
  • you can, however, turn a perfectly good recording into a bad recording by messing about with it too much

or, to put it differently:

  • get it right at point of capture
  • do as little to it as possible thereafter

I misunderstood; I added the left track to the right on the second pass. Can you explain how I “split the stereo track, discarding the empty right channel and defining the remaining left channel as mono instead of left.”
I would also love to learn about Koz’s Four Horsemen, do you have a link?

Just use the Track Drop-Down Menu to “Split Stereo to Mono”, then click the [X] on the bottom empty track to remove it.

More examples at .

I’ll pass on the Four Horsemen.


Thanks Gale,
This is a big help. It’s easy once you know where those menus are lurking. And thanks for the link.