I have Logic pro x & apogee duet, the mic suddenly stopped working, it gives alot of rumbble (air) when we turn the mic volume up, but it does not record any audio, when we go to sysytem audio preferences of the osx lion system and we choose mic input , it says this line has no input signal but when we turn up the mic volume on the apogee system we see a signal( the rumbling), the are times when it captures wave signals and we see it but its just rumbling, at other times its just flat line and yet another time it has small wave forms but never any sound recording output, what caused it and what can we do to fix it. thank you

What Mic are you using? Did the Mic work before? Make sure you have the input set to Mic and not Instrument on the Duet. You can check this on the Apogee Maestro software for the interface.