Hey all, sorry if this is a repeat of an oft asked question. I searched but could not find it.

I'm trying to find out about a good location for subwoofer(s) in my CR and how to calibrate it/them. My limited understanding is that time alignment can be an issue with them.

My current layout is:

CR:16L X 13W X 9 1/2H(average of vaulted ceiling). Walls are skewed 5 degrees out from mix position. Lots of various absorbers, corner absorbers, diffusers throughout.

Monitors: Wharfedale Diamond 8.2 Pro active monitors.

Monitor location: Soffitt mounted, 6' apart. Front face of soffitts are angled at 30 degrees so monitors point directly at mix position, which at 6' out is close to the recommended 38% of the distance to the back wall.

Directly in front of mix position is a 4' X 4' window to the outside world, so i can't place a sub there idirectly between the speakers. From a budgetary standpoint, I'd prefer to only have to buy one, active sub, but I'm open to other options.

Questions:

1-If I have the space, am I better off placing a pair of subs directly below/above the soffitt mounted speakers, facing forward? I'm thinking there shouldn't be any time alignment issues if they're coming from essentially the same spot as the monitors themselves.

2-Or does it work fine to buy one sub that is designed to be placed on the floor between the speakers?

3-Once I have such speaker(s) in my posession, how do I best calibrate the volume of the sub(s) relative to my monitors?

4-Do most subs come with time aligning software, or is it usually done in the recording/mixing program, or is it generally done simply by location in the room? (I have Cubase SE3 if memory serves)

Thanks. I hope I've spelled out the questions adequately.

Cheers
Keith