Trying to even out Audio Track

I record with a co-host and I always find I have a problem getting their volume even to mine. The problem is that while their normal volume matches mine, their volume tends to dip at points in the recording. Everything I’ve tried that even came close to working seems to add a reverb effect to their audio. Would anyone be able to help me out? Is there a simpler way to get even volume across a single track?

I have had good results using Chris’s Dynamic Compressor to even out voices. However, I record in stereo with about an 80% separation. Your mileage may vary.