You will have to recalibrate your system so the sub is at the same dB's as the other speakers, normally 75dB's. This can be accomplished using an SPL meter, or the built in tones/mic of most receivers. With the EP subs, you will find that the volume (gain) knob will most likely have to be very low, like 6-7 o'clock position, to set to 75dB's.
Most leave trim on Flat for the flatest frequency response, however, some smaller/med rooms might enjoy the half or full setting which elevate the frequencies in the 30-50 Hz range, only time will tell for you.
The crossover knob should be on bypass, or cranked to the highest setting since your receiver handles the bass management. I would start with 80hz on the other speakers. However after running Audyssey on my Denon, I use 90hz for the Qs8's and 80hz for the other speakers.
