I'm wondering about Rel's recommended speaker-level connection.
There seems to be some sense in giving the sub the exact same signal as the front speakers as Rel maintain, but the disadvantage of this sort of connection is that, if you are equalizing your sub, you then only have controll of frequencies bellow where your mains natrurally roll off, as opposed to bellow 80hz if you are lusing line-level and bass mgnt.
It would depend on where you are crossing your main speakers and why you are using EQ on the sub. If you are using EQ on the lowest octaves produced by the subwoofer, why not use EQ on the main speakers' output also?