Is there a way to un-crossfade an audio track that has been cross-faded? I have tracks I've recorded from Internet Radio, and they're crossfaded and then split into tracks.

It's pretty much impossible with any sort of quality. Separating individual instruments/voices from a mixed signal is really hard.

Edit: If you have one of the two tracks on its own, then you're in business.

I'm a wizard, Hydrogenaudio is my spellbook and Cool Edit my wand...
There's no way to achieve what you want.
Whenever you want to separate parts of the audio or to affect only parts of the audio by some processing procedure, the program needs to have criterions to decide what to affect and what not. These can be generally one (or any combination) of the three:
spacial position
frequency
loudness
Frequency & loudness work very well on noise reduction, for example. As for de-crossfading, the tracks are hopelessly mixed into each other. It's the same like dividing a studio record into the single tracks that it has been mixed down from. (rather more difficult than that - impossible)

No, not unless both the original and mixed version are lossless files which come from the same original and haven't been re-digitised. Even then, it would be very tricky to match the crossfade envelope to remove it.

With internet radio, you have a lossy codec in there, which will make the job impossible. Subtract the original, and you'll just hear artefacts. Subtract a different lossy coded version, and you'll hear two sets of artefacts superimposed.

Cheers,
David.