I hear you guys alway talking about this and I'm thinking to myself what is the big deal with this stuff? I set my speakers and sub where is was convinient, (still trying to follow the typical set up) and it sounds awesome. Even across the greatroom where its set up on the living room end, across the dining space in the great room and all the way in the kitchen (a good 25-30ft away from the "sweet spot") it sounds great. Clear dialogue and great bass. All I have is a take 5.2 set up and the matching sub. By far not a relatively "great" system. So what does the SPL meter and avia(sp) calibration disk actually do? Could I benefit from them if my system already sounds great? Edit: I put this in this forum because I figured calibrating your speakers has to do with speakers.