I’m using M-audio as interface for Audacity on Mac. When I input stereo source, it only plays back on 1 channel. Why?
Your interface probably has two inputs, one of which is occupied by the mic and the other one is empty. So when recording stereo, one channel records emptiness.
I have a cord with 2 male 1/4 inch jack on one end (stereo), and the other end a 3.5 MM male going to M-audio. I have a stereo adapter placed on the end of the 3.5 MM end and ran into 1 channel on the back of M-audio board thinking I would get stereo sound in Audacity and I could not.
You are absolutely correct! I ran two individual 1/4 inch jack cords with males on both ends into channel 1 and 2 on back of M-Audio, and Voila, I see and hear both channels in stereo in Audacity. Not sure if it is true stereo but sounds very close. Thanks for your help. You are a lifesaver