Mojo the 400 does not hit at all like the 600. To get what you are asking you need dual 500s or 600s. Also flipping the phase switch and its effectiveness on the speakers will depend vvery much on where the sub is placed relative to the speakers.

I suspect going the acoustical treatment and bass trap route will help give you the kind of transparency you are looking for. Treating my HT with wall panels and bass traps made a bigger difference in improving sound quality, than any component I have ever purchased.

John