Brand new to recording, I seem to have everything working correctly on my MacBook Air. Only issue I'm having is when I record something, and go back to record over it, or add a new track, what I previously recorded gets lost/drowned out by what I'm playing live. It's like the original track I recorded doesn't come through my headphones so I have no way of knowing where I'm at in the song. if I turn the mixer knob to the right I can hear it but my voice lags and throws me off. Please help me out!