Way to go guys! Very useful responses so far ... u don't know how to set up... I tweak... I measure .... patience ...
Jb8312, I have seen on your system page that you have the Verity Audio Parisfal Ovation speakers. If I am not mistaken their bass module can be placed so that the woofer fires either towards the listener of away from him (i.e. towards the back wall). Because some of the low frequencies will be reproduces by the Parisfal bass modules and also by the subwoofer, the orientation of the subwoofer with respect to the bass modules and also the placing of the three bass sources in the room is very important. Thus, your situation is not exactly the typical case.
Try to following set-up procedure:
Part One: determine decent parameters for the crossover and volume settings of the subwoofer
1) Play a double bass jazz piece. I usually make a loop using the loop function of my cd player. Most often I use the beginning of the track 3 from Norah Jones' Come Away With Me album, i.e. the first measure of the starting bass piece (3-4 seconds).
2) Than using some common sense settings for the crossover and volume settings of the subwoofer move the subwoofer around the room. You are looking for the ideal place to placed the subwoofer, i.e. the position that will give you no significant resonance or nulls at the listening position. This step is best accomplished with the help of a friend/wife.
3) Once you have found a good place for the subwoofer start playing with the volume and crossover settings for the subwoofer. Your goal is to make the double bass notes to sound all even (i.e. having the same volume) and tight (when you close you eyes you should be able to imagine that these notes are produced by the double bass cords).
Part two: determine the best place for placing the subwoofer
1) Now with the volume and crossover settings determined in Part One, move the subwoofer in your listening position.
2) Play again the same loop with the jazz walking bass and walk around the room looking/listening for the places where you get the best bass sound. Here you should look for the places with good sound when your ears are about at the same height as in your listening position. Most likely you will find more than one palce. Mark the one that is convenient for placing the subwoofer.
3) Change the phase of the subwoofer and repeat step 2.
Final step: move the subwoofer to the place (determined in the previous step) that gave you the best bass integration, and of course keep the phase setting that worked best. At this point it might still be necessary to slightly adjust the crossover and volume settings of the subwoofer but only slightly.
After caring out this procedure, you might want to repeat it with the bass cabinets of your speakers reversed. You never know, you might get even better results.
I have a REL Stentor 3 subwoofer and I have used this procedure successfully a few times already. This "procedure" is a bit of a hybrid between what REL recommends and what I have read here and on other forums. I "come up" with it while looking for bass in my new room. I ended up with the REL somewhere between the two speakers and I get much better bass integration and volume than when placing the subwoofer in the corner as recommended by REL.
Good luck and keep us posted!
Paul