Overdubbing effects to imported audio files
I have read the help tutorials and online videos, but still am unsure about how to go about this: I import a previously recorded audio file to tweak in Record. I apply the active fx I want to add, but when I hit the record button, the imported trrack gets erased, so I underdo, and click on the overdub button. I don't see any meter activity on the overdubbed track, just track one with the imported audio. How can I be sure the effects I've selected are actually being applied to the imported audio file? How do I then export the remixed audio as a wav file? The first time I attempted this, the file was exported, but no audio was heard when imported into iTunes. Someone please, please help me!!