In the past, Iíve recorded on computers through input and output jacks and have gotten some clean, great sounding recordings. Now Iíve got a MacBook Pro that has only one input for mic and headphones. Iím recording with a USB mixer so Iíve figured out finally how to have the recorded tracks coming through the headphones while the usb input plays through the speakers connected through the mixer. Trouble is, I canít get the track Iím recording to come through the headphones too. I had to set up an aggregate device to get the already recorded tracks to come through the headphones while I record the next track. While I can live with that when recording instruments, I really need the vocals to come through the headphones while recording. Man itís frustrating me.