Flipping stereo channels?

How do you flip stereo channels, so that right becomes left and left becomes right? and I need to do this while exporting multiple.

The drop-down menus in the panel to the left of the blue waves has provision to split, assign, and then recombine tracks. Do this before you Export Multiple.

OK. That doesn’t seem to work. I wonder why.


Click on the track name and select either “Split Stereo Track” or “Split Stereo to Mono” (doesn’t matter which).
Click on the track control panel (the box on the left end of the track) of one of the tracks, taking care to avoid the sliders (somewhere round about where it says the sample rate is a good place to click), and drag the track up or down so that the track order is reversed.
Then click on the name of the upper track and select “Make Stereo Track”.

Or, if you want to avoid the risk of clicking the wrong place you can use again the pop down menu from the track name and choose “move track down” (if you clicked the upper track menu), or “move track up” (if you clicked the bottom track menu)

So, um. What do “Right Channel” and “Left Channel” in the dropdown menu do?

Generate a tone with no tracks in the project - a mono track is created and filled with tone. Play back the track - both playback meters move. Change it to “Left” and play it back - the left channel meter moves and the right doesn’t.

If you have two tracks one above the other and do “Make Stereo Track” from the track drop down menu in the upper track the designations of Mono/Left/Right are ignored - the upper track becomes the left channel and the lower track becomes the right channel.

– Bill

“Right Channel” and “Left Channel” in the drop-down menu apply only to mono tracks. They allocate the destination of the data for that mono track.

The (playback) output from Audacity is a “stereo bus” - that is, two channels of audio. This is regardless of what tracks exist in the project. (this is the same as how most other audio applications work).

By default, a stereo track will output the left track channel to the left audio bus and the sound will come out from the left speaker. Similarly the right track channel will be mapped through to the right audio bus and come out from the right speaker. For mono tracks, the audio track data is mapped through to both channels of the audio bus and will come out through both speakers.

The “pan” slider provides a way to change how the audio data from the track is mapped to the stereo bus. Pus the slider to the left and more of the data is sent to the left than to the right, push the slider to the right and more is sent to the right than to the left. In turn this means that more of the sound will come from either the left or right speaker thus producing the “pan” effect.

The practicalities of how Audacity pans tracks:
For mono tracks, if the pan position is centred, then the track data is sent to both left and right channels. For example if you have a 440Hz sine wave with an amplitude of -6 dB, then a 440 Hz sine wave with amplitude -6 dB is sent to both the left and right channels of the stereo bus.
In this example, if you push the pan slider to the left, then a 440 Hz sine wave of amplitude -6 dB will still be sent to the left channel of the stereo bus, but the signal sent to the right channel of the audio bus will be attenuated so that a 440 Hz sine of amplitude less than -6 dB will be sent to the right channel of the stereo bus.

Similarly, with stereo tracks the pan slider attenuates the left or right channel depending on which way the slider is moved.
This is a more simple mechanism than used by some other applications as it does not involve mapping data from one channel to the other, but as well as the simplicity it has the additional benefit of preventing inadvertent overload of one channel when the pan position is off-centre.

If a mono track is set to “Left Channel” then the audio data is mapped entirely to the left channel of the stereo bus. Similarly setting the track to “Right Channel” will map the signal entirely to the right channel of the stereo bus.

“Mix and Render” takes the data from the stereo bus and renders it to a new track. As the pan position affects the audio signal that is sent to the stereo bus, the resultant mix will accurately reflect the pan positions.

When combining tracks with “Make Stereo Track”, the data is taken directly from the tracks, so the pan position slider has no relevance. The upper mono track data is put in the left (upper) channel of the new stereo track and the lower mono track data is put into the right (lower) channel of the new stereo track.

“Split Stereo Track” …drag the track up or down…“Make Stereo Track”.

OK, thank you, even I can get it to work. Two things:

  1. I feel a little better that reversing channels wasn’t completely obvious.

  2. Audacity has very polite users. I really was expecting someone to say, “Hey, DUDE! Put your headphones on backwards!” Which is what I was doing, but I felt bad doing it.

    D. McG.

  1. I feel a little better that reversing channels wasn’t completely obvious.

You think?

Audacity sloshes back and forth between stereo and mono too easily for my taste. The explanation doesn’t allow for mistakes, like what happens in a mono show with an expected mono export if you touch the pan controls by accident? Does it even tell you the show is now in stereo?

I really was expecting someone to say, “Hey, DUDE! Put your headphones on backwards!” Which is what I was doing, but I felt bad doing it.

We can’t do that. We have to assume the worst case condition that the user is trying to deliver a product to a company or producer and the terms are not negotiable.

We might call you “Dude,” though.


Has there ever been a feature request for a “Mono/Stereo” option in the Export dialogue?

Generally I mix down the project before I export - this gives a much better idea of what the exported file will be like. With multi-track projects it’s the only convenient way to amplify the mix close to 0 dB prior to burning to CD.

I do the same too. I never export multi-track projects without mixing and rendering first

We try, we try - we also remove the impolite/irrelevant posts and often the impolite poster too!

We like this as a cozy sane corner of cyberspace where “women & childern” can visit comfortably. :slight_smile:

And thanks for the feedback “Dude”. :wink: