This is my first post. Im 16 years old and I've built up a fairly good system. B&W DM603 S3 and B&W DM602 and a LCR600 all connected to a Denon AVR 3803. I need someone to explain to me in baby steps how to tune in my sub (Polk PSW450) with the rest of the system. How do I listen and when do i know if it is set correctly. For eg how does the crossover work and if a croosover setting is set on the amp(80Hz)must I still adjust it on the sub? Any help will be appreciated!