REL Sub demo
So my REL Subwoofer arrived.
Grate packaging, safe and neat.
Its been two days now that I test it thoroughly and I am trying to find the right adjustment and placement.
Starting first with placement I will try to give the best description I can.
CONFIGURATIONS:
I placed the sub behind the left speaker to a corner. Te sub though is not exactly behind the speaker as the manufacturer recommends.
Now I have the three adjustments on the sub, because the connection is a Neutrik Speakon high-level input for direct connection to amplifier.
I am a little confused with the adjustments of the level of the sub, the phase ...is it supposed to be 0 or 180? and the crossover.

My speakers Magnepan MG12 are from 45-22kHz ±3dB
Am I supposed to set the crossover at 45 or less than 45?
I didnt think that it would be so difficult.
I would appreciate all your thoughts and advices.
The SOUND:
Sound comes out grate and I am sure that when I set it up properly it will be the best.
One think I dont like is the roaring or rumbling of the base.
I dont like tso much the home cinema so I will try to avoid it.
Please share your thoughts and your ideas
Thank you