Two different mono channels in 1 track

[rorser]

I created an .aup project that is one track of two +++different+++ mono recordings--one on the L channel and one on the right.
How best to cut one channel and append (paste) to the end of the other?
And, then how to make that mono channel appear on both L and R channels so I have the same mono signal coming from both L and R speakers?
Gratefully,

[kozikowski]

First make darn sure you have a good file of your original work. I would probably export as WAV in addition to the Project.

Then you can use the tools under the little black arrow on the left.

Split Stereo Track > Delete one track. Edit > Duplicate > Make Stereo Track. Export as WAV or save a new, different Project.

Open the original Project and go through that whole thing for the other track.

That's the short version. Let me know if you can't find some of the tools.

Koz

[kozikowski]

Do Not try to save the new shows using the same file names. Once you step on or damage the original show, you're toast.

Koz

[steve]

I created an .aup project that is one track of two +++different+++ mono recordings--one on the L channel and one on the right.
How best to cut one channel and append (paste) to the end of the other?

What exactly are you doing? Transferring two mono recordings from the same side of a reel-to-reel tape?

[kozikowski]

It could be two sides of a Pamela/Skype recording.

Koz

[ignatz]

I did some experimenting and this seems to work. There may be a more elegant method.

Split stereo track from the black arrow/triangle

Put cursor in top channel

Edit, move cursor to track start (cursor is now at beginning of top channel)

Edit, select cursor to track end (top channel is now highlighted)

Edit, copy (top channel is now on clipboard)

Put cursor in bottom channel

Edit, move cursor to track end (cursor is now at end of bottom channel)

Edit, paste (top channel now has been appended to end of bottom channel)

Edit, move cursor to track start (cursor is now at beginning of bottom channel)

Edit, select cursor to track end (entire bottom channel containing both original channels is now selected)

Edit, copy (entire bottom channel containing both original channels is now on clipboard)

Put cursor in top channel

Edit, move cursor to track start (cursor is now at beginning of top track)

Edit, select all (entire top channel is now highlighted)

Edit, paste (top channel overwritten with contents of clipboard; both top and bottom now have same content)

Make stereo track from the black triangle/arrow

Export

I tried a couple of other variations that will probably play back on both L and R channels, but these other variations showed as a single channel when reopened in Audacity. The method outlined above opens as two channel.

[steve]

Very thorough ignatz.
There's also a lot of keyboard and mouse shortcuts that can make it a lot quicker (see bottom of post).

I tried a couple of other variations that will probably play back on both L and R channels, but these other variations showed as a single channel when reopened in Audacity.

I would usually go for a method that produces a single channel mono track. The sound from a single channel mono track will be identical to a 2 channel mono track (and will play through both speakers), but if exported as a WAV file then it will be half of the size of the 2 channel version, and if exported as an MP3 file it will be higher quality if exported at the same bit rate than the 2 channel version.

There is also a more simple way to make the single mono track into a 2 channel mono track (if required).

Edit, move cursor to track start (cursor is now at beginning of bottom channel)
Edit, select cursor to track end (entire bottom channel containing both original channels is now selected)
Edit, copy (entire bottom channel containing both original channels is now on clipboard)
Put cursor in top channel
Edit, move cursor to track start (cursor is now at beginning of top track)
Edit, select all (entire top channel is now highlighted)
Edit, paste (top channel overwritten with contents of clipboard; both top and bottom now have same content)
Make stereo track from the black triangle/arrow

The short method is to select the bottom track, then "Duplicate" the track (Edit menu > Duplicate).
The top track is no longer required and can be deleted by clicking on the [X] in the top left corner of the track
The bottom track and the duplicate can then be merged into a 2 channel track as ignatz describes (select "Make Stereo Track" from the track drop-down menu).

Useful shortcuts:

Ctrl+A (select All)
Ctrl+C (Copy - the data that is cut is now on the clipboard and may be pasted)
Ctrl+X (Cut - the data that is cut is now on the clipboard and may be pasted)
Ctrl+V (Paste - the data on the clipboard is pasted to the track)
Ctrl+D (Duplicate - copies the current selection to a new track)
HOME (move cursor to beginning of track)
END (move cursor to end of project)
K (move cursor to end of current track)
These last three keyboard shortcuts can be used with the SHIFT key held down for extending the selection - for example, HOME, then SHIFT+K will select from the beginning to the end of the current track.

Double click on a track (selects the track)
Click on a blank part of the track information box (alternative way to select the track, but take care not to nudge the slider)

[ignatz]

The sound from a single channel mono track will be identical to a 2 channel mono track (and will play through both speakers)....................and if exported as an MP3 file it will be higher quality if exported at the same bit rate than the 2 channel version.

Steve:

I have read that playback of single channel through both speakers typically works, but may not--depending on the sound card. Is that not true? Or will it invariably work, regardless of sound card, hardware, connections to a home stereo, etc?

I've got a bunch of single channel tracks that play OK through both speakers now, but wonder if a sound card I have 5 years from now may foil that and play only L or R, not both. Most of my playback is through PC linked to home stereo.

Can you expound on the bit about "higher quality if exported at the same bit rate than the 2 channel version"? I can understand how a single channel version would save space, but the "higher quality" thing throws me a bit. I'm guessing you'll say something about all the bits in a single channel means more info in that single channel, therefore higher fidelity?


And therefore, for a mono 2 channel source (both channels (near) identical), a 96k bit rate single channel export would have higher quality than a 160k bit rate 2 channel export and have the same quality as a 192k bit rate 2 channel export----i.e., 96k bits per channel.

That's how I have it in my mind, tentatively. I just remain nervous about globally converting 2 channel mono to single channel mono.


Thanks for the shortcuts; I am very mouse-oriented and no doubt should try to learn a few pertinent shortcuts.

[kozikowski]

<<<I just remain nervous about globally converting 2 channel mono to single channel mono.>>>

That you can do with no damage. Export the mono file as a WAV file and there's no damage there, either. That file can, at any time be converted back to "stereo" (two channel mono) if you need it.

What you can't do is create MP3 or other compressed format. That creates damage -- always. You just get to pick more or less damage with the bitrate and there's less damage with a mono file at any one fixed rate.

Never archive or do production in a compressed format. Really Bad Things happen.

Koz

[ignatz]

Export the mono file as a WAV file and there's no damage there, either.

I assume you mean ONLY if the mono file is a WAV or other lossless format?

If so, I will continue my present policy---being nervous about it. My files are mp3.

I gather there is no way, with Audacity or any other app, to open an mp3, fiddle with it, and resave as mp3 without further compression? I've done it with no audible degradation, but remain nervous and do it sparingly.

Come to think of it, I have seen some barebones editors that can supposedly do a basic edit of an mp3 (cutting a segment, doing a fade) without recompression--allegedly, I say allegedly.