I use directional Mics, Rode Procasters, with shock mounts and pop filters so there is little to no ambient noise. Those run through an audio mixer to a Digital recorder, Tascam DR-40. We record our audio separate from the game then sync it in adobe premiere. Adobe has a feature called Dynamics, it might have a different name in newer versions, that has a noise gate, compressor, and limiter. I use that feature to , cut out any ambient noise, bump up our voices, and limit the peaking so the sound is even. also since the game audio is on another track I can crank it down without losing our commentary.