I bought an MA-300, one xlr microphone, a 25' xlr cable. I set the camera to mic att, recorded an interview in a settings with a lot of background noise. I was wearing headphones and could not really make out the sound sources while recording, I adjusted the audio to have it come through the microphone only without success. The audio is mixed, I thought the on-board microphone would shut off when I was using the MA-300, like it does when I plug a 1/8" microphone line into the camera. I tried splitting the audio into two channels (L & R) in Vegas 9, so that I could eliminate the background noise - not possible. I am really disappointed, because I have been trouble shooting audio with the GL2 for some time without satisfactory results. I started out with two (low end Azden wireless microphones) only one microphone registers (even with new batteries in each and green lights on the hot shoe mounted receiver - what is recorded is just one wireless microphone's input). So, now I just use one wireless microphone and my guests pass it from one person to another. Should the camera be set to wl.remote 1 or 2 for two wireless microphones? Any ideas?