My guitar is plugged into input 1 and the H4n is plugged into my iMac through USB. When I play something, there are levels on the H4n, but, even though I have my line-in on my Mac set to H4 and everything, I can't see levels in Audio settings ("the selected device has no input controls"?), and therefore not in Cubase or GarageBand, even after setting the inputs for both to the H4. What could I do? I have the latest H4n firmware. Thanks!