2000 Honda Civic - I have 6.5s in front and 6x9s in back running off stock Honda deck. I am adding Alpine 9843 HU and 10" Punch sub powered from 150W Alphasonik amp. 4 Questions: 1) I am getting buzzing/vibrating from rear 6x9 in what I think is 80-120Hz range. Should bass blockers fix this? 2) Is there a way to "tweak" bass settings on Alpine HU so I don't need a passive crossover? 3) What freq do you recommend I cut off the bass (which is designed for faster/tighter bass)? 80? 100? 120? 4) WHERE THE HECK IN CANADA CAN YOU GET BASS BLOCKERS>? Crutchfield doesn't sell to Canada, and I can't find ANYONE who sells 80Hz or 100Hz 6 OR 12db! (Even E-Bay)! GlassWolf rocks the house! He got me hooked on ecoustics.