So I have connected my M-Audio FastTrack and my M-Audio Producer USB through to Garageband and they work individually. However, when I enable multi-track recording and try to record a guitar track (through the FastTrack) and vocal track (through Producer USB), everything comes through the Producer USB.

I've got the settings so that Prod. USB is mono 1 and FastTrack is mono 2 (which is the only setting it can be). I don't have an adapter to put the mic into the FastTrack either. This is really frustrating when I'm trying to balance volume and mix.
What am I doing wrong and how can I get a separate guitar and separate vocal track?

Thank you!
The FastTrack works because it's class-compliant, so you don't even need its drivers to make it work.
The mic works because you enabled it in the settings.

For what I know, you just can't do what you want.
Name's Luca.

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You may need to create an aggregate device in your audio settings. This will collect all of the ins/outs of the two interfaces and tell your DAW that it's one big interface. This is VERY easy to do on Mac, but it's best if you google the process and follow step-by-step instructions for it, rather than listen to my fuzzy recollection of how I've done it in the past haha
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