my new subwoofer/ help please on settings

hi all

as some of you know i was the lucky winner of a competiton on another website.

i`m using the sub with a AEGO 5 processor /sub/speaker system.

the sub with the AEGO 5 all the speakers connect to this and there is a aux sub imput/output. so ive connected it to there , so far so good ,

ive then turned volume on the sub on the AEGO 5 right down to 0. cant turn it off as it turns the rest of the speakers off too, got sound coming out and it sounds good/ loud on the back of the new sub VELODYNE VX-10 there is a volume button this ive set to just about a quarter?
and a cross over knob ? where should i set this ? i have it just over 80 at the moment. there is a in/out type button for phase sould i have this in or out? out is 180. in is 0.

big thanks to all

here is a picture of it dwarfing my AEGO 5