Audio processing in Ableton Live is stereo by default. However, if you import a mono sample that only has audio data for one channel, Ableton doesn't automatically correct the mix to fill the stereo field, so you will only hear sound out of one speaker -- and adjusting the track's pan knob won't help because there is no audio in one channel to pan to. Use the Mono audio effect to manually remix a one-sided mono sample into stereo when this situation arises.

Step 1

Select the audio track in Session view. Test the Track Pan knob to ensure that the sample is actually one-channel mono.

Step 2

Select "Audio Effects" in the Browser, and then expand the Utility effect category by clicking the small triangle next to it.

Step 3

Double-click "Mono.adv" to add it to the selected track. The effect controls appear in the Device View area. The Panorama parameter adjusts the sound's location in the stereo field; it is set to "C," or center, by default, so as soon as you add the effect, the track is made stereo.