Originally Posted by John Schneider
I may have missed it, but how is your sub connected? I used the RCA (unbalanced) on my f113, and was happy, but not blown away. Then I saw some posts that suggested that some subs were not correctly summing left and right inputs if using a single connection. Pulled out a "Y" connector, fed the signal to both L&R, BINGO!
Sounded much better, confirmed I had gained 3 db with RS meter. I've been backing off on levels ever since (seems like I would just need to lower my sub outut by 3 db ont the Lex, but no).
ALL subs that are not toys are calibrated to use ONE mono input from a bass managed receiver going into ONE of the RCA inputs. That's why there is a MONO SUB OUT on the receiver.
By Y'ing the cable you are doing nothing more than turning the bass up 6dB, (not 3dB). The 2nd RCA connector is there in case you are using a setup with a stereo (i.e. 2-channel) system.
In fact every sub that has multiple inputs such as 2 x RCA's and 2 x 3-PIN connectors (and even 2 x speaker connections) sum all of these together internally into mono anyway.
With most receivers, you should notice that if all the levels are set at "0" AND the sub calibration is at its "0" or reference that you should get the same 75 dB reference noise nearfield from the sub.
Of course all those reference levels are useful as a starting point and at the very least you have something to return to when you get hopelessly confused...and want to start over.
To further clarify, the "real" THX and Dolby reference level is 85dB, but somewhere about 100 campfire stories ago, some receiver mfg decided that 85dB pink noise frightened people (and pets...). The internal levels and all that that entails (0VU, digital headroom, analog headroom, disc reference level, etc) are still really set at 85.
Some receivers, like the Anthems are smart (and clever) enough to allow you to set the "0" refence either where it belongs or somewhere where "you" like it, to assist you with meter readings, for example.