Heard something the other day that seemed to make a lot of sense so, from that, Ill pass it on and also ask a question to your real audiophiles out there! When setting your sub up always leave the DB gain level on the processor/amp at +/-0db. Never, tune it down via the amps channel level screen. In doing this you increase the signal to noise ratio. In short, leave the processor at the 0db level and use the subs on-board amp to set it to reference level. Sounds obvious, but I never thought of it before. Sub level now at 0 and subs volume adjusted accordingly! Question: If this signal to noise ratio exists with the A/V to sub, does this also apply when you connect a power amp to your A/V. For example, I have connected my Arcam P-25 to my Denon 3802. With all channel levels set to 0, the Arcam registers at around 81-83db and thus I need to tune down the Arcam levels (via the Denon) by around 4db a channel. Is this then causing a higher signal to noise ratio and, in short, providing a slightly (even if not audibly) worse sound quality?