Hi everybody!!: I only have experience with front ported speakers, e.g., JBL S-312. I'm interested on the Axiom's M-60 or M-80 speaker, but I see they are front and back ported. Do these speakers need to be very far from the walls?. I'm concerned as to how far I would have to place them from the wall, I only have about 20 inches (about 51cm) max from the wall to place them. I would have to toe them in with an angle of about 18 degrees. I would appreciate you input.