@Rleff
I use a Velodyne powered sub in my listening room as well.
I was watching the volt-amp meter inline with the amp as the non-powered woofer would engage for LFE and I was astounded at how much current it drew all by itself. That's why I opted for the powered sub - with a 100 Hz crossover setting on the fronts.
Contrary to what I have read concerning the maggies, I have no problems with current draw - I do not view them as "inefficient" speakers.
I can watch the volt-amp meter rising as I turn up the volume however, its too loud to enjoy if I really want to dim the lights. The Velodynes allow for phase correction so I don't have any problems.