I was wondering i live in canada and the cheapest spl meter is $90 and i have know idea where to get a avia disc other than online, what kind of stores if any have these discs? and how much better could it actually sound i have a da4es all my channels are turned to +5 and i sounds good to me because i like lots of sound out of rear and back surrounds. i've gat a cerwin-vega, paradigm setup with a ps-1000 sub how much difference do you think it would make and would it be worth the $150 to buy the gear? and does the disc tell you what to set everything to? i look forward to hearing from you!