I just got SPL meter & i read everywhere that the best setting is to set it to 80db as Dolby suggested but i have some questions: i put my SPL at C weighting & slow response & 80db & i hold it looking upwards & on ear level. 1-What should i put the Master volume on the Reciver at??coz i don't get any response from the SPL pointer until my Master volume reaches -9.5db with the speakers @ +10db @ that the SPL reads 80db,SO am i doing this right??? 2-Do i set each speaker at 80db or all the speaker @ 80db coz when i set eachone @ 80db when watching a movie or listing to music with all speakers working it becomes very very loud also the amp is near clipping,So do i must use a test tune from all channels @ 80db??? my system: Yamaha RXV650 Wharfedale Diamond8.4 fronts Wharfedale Diamond8.3 rears (very soon,Using another rears for now) Wharfedale Diamond8center 100W powered RCA 10" subwoofer with crossover@60HZ 100W powered by external amp Optimus 12" subwoofer with cross@80HZ anyhelp please guys.