Monitoring While Multitracking--w/o Latency?, How do I monitor during playback w/ USB? Options

[marley]

Hey Rockers,

I know similar topics have been beaten to death, but I can't find the answer to this specific question. I've got a 1.25 Ghz iMac with 1 Gb RAM, and I just bought a used M-Audio Duo to start multitrack recording. I am so far only using Garage Band, though I plan to advance from there, and I have found that playing through the software results in an unacceptable amount of latency, even on the "low latency" GB setting. I figured out how to use the "Stand Alone Mode" button on the Duo to monitor through the headphones without latency. That's great, but I can't find a good way to listen to my existing tracks while monitoring the track I am laying down.

What I've been doing so far is wearing headphones to monitor the live track from the Duo, and having the rest of the tracks play through the computer's speaker system. This sort of works, but is less than ideal. Is there a better solution, or is this a limitation of USB? I'm sure some of you smart people know how to get around this dilemma. I'd love to hear your suggestions.

Marley