lav mic help

Hi,

I've recently helped with the audio for a two-person interview, and I was asked to use a two lav mic setup. I wanted to use a boom mic too, but there wasn't the budget. So now I'm mixing two mono channels of lav mic audio, and am having trouble with leakage between the channels. When people talked on top of each other, in particular, you hear an echo from the other track. I have used volume ramping to isolate each person, but when they talk together, it really sounds weird. I have captured room tone to make up for the gaps in the interview, and the producer doesn't want any background music, so I'm trying my best to mix, but it's hard, because the room tone sounds so much different than the lav mic sound. Any advice on the two lav mic set up for interviews, and how I can mask gaps? Also I'd appreciate advice on repairing a couple of lower level clips, and how to mask the noise floor hiss when I raise the volume?


Thanks
J.