a big thank you to all regarding opinions on the bk xls 200,i was considering the REL quake but after a few hours on these forums i chose the bk........i have only set it up in a very basic way and have to say i'm impressed but of course i need to set it up to near perfection? any suggestions? at the mo i have the crossover in the 'LFE' position the phase i haven't touched so it's a 0 and volume just touching 2 on the dial. it seems many people have different opinions on 'phase' what is the correct explanation as to it's purpose??? oh the sub is only used for home theatre with amp crossover set at 80hz......any ideas would be great!