When preparing your mixes for a mastering session, we typically get the question, "Should I take the L2 and compressor off the mix bus?" My first thoughts run through my head like asking why or what are you doing. . . but I refrain myself. I go on to explain that mastering engineers basically have 2 tools at their disposal: compression and eq. If the mixes are already compressed within an inch of their life, it ties one of the mastering engineer's hands behind their back.