I have to say, I was surprised at low volumes how much this driver moves and thinking that I thought, well it won't go loud, but it appears the XXLS400 puts out much more excursion than what I am used to (Z5500 10" driver), really does move, looks like the peerless driver it was almost 1.5cm and wasn't even clipping!
Saying that, 180W vs 400W, I wouldn't say it's over two times as powerful in terms of output?
Don't get me wrong, I'm comparing ability in terms of output, in terms of quality, the XXLS sounds much more refined, and on the low frequencies, the same frequency, say 30Hz, sounds fuller and lower as weird as that sounds.
Another thing, using the Neutrik connector, if I turn the denon amp off, the sub has a loud humm, so I have now choice but to turn the subwoofer off at the back, it's not a big deal as that's what I'd likely do anyway to save electric.