[m-fine]

5) To set you subsonic filter, go to the crossover setting tab (or menu on the front panel) and create a high pass filter. You will then be able to select butterworth (but) fron the list of available filter types. The number after the type is the db/octave drop, so 48 is twice as steep as 24.

6) The delay setting will be the most difficult. I think my approach would be to measure the distance from each sub to the listening possition and put the delay setting on the output of the one that is further away. If the subs are 4 meters and 6 meters from the seats, but a 2 meter delay or 5.82 ms delay on the further one and leave the closer one at 0. You can than use the input delay or the distance/delay settings on your receiver when you integrate the subs to the front speakers. In this case, as a starting point, I would use the actual distance to the main speakers and the distance to the closer sub minus 1 foot as a starting point. The reason for the minus 1 foot is the processing in the DCX takes some time and introduces a bit of delay. From that point run some sweeps or better yet use the RTA feature of the new REW to fine tune the sub delay to minimize any cancelations at the crossover frequency range.

7) I would strongly recomend you not try to EQ each sub individually. My first crack at it would be to EQ them as one sub by measuring the combined response and trying to flatten it first by moving the subs if possible (a foot or two matters) and then finally adding a few PEQ filters to the input. If that does not work, or the capabilities of the subs are drastically different, you can make individual adjustments, but any change to 1 sub will affect the room response of the other when played together and will also influence the integration with the mains. In otherwords it gets very complicated.