EDIT: Space is a premium so a simple XLS400 or Monolith upgrade wont work. I'm looking for a replacement sub that is ideally Forward-Firing AND ported. Possible options so far: Velodyne EQ MAX 8 (180w RMS) drops to 17hz Paradigm Ultracube 10 (650w RMS) [sealed box] drops to 22hz - a shade pricey tho! Sunfire HRS 10 (1000w!) [sealed box] drops to 20hz - again a shade pricey! Sunfire SDS 10 (250w) [dual speaker], but only hits 30hz SVS SB12 NSD (400w) [sealed box] drops to 23hz ....I'm on the verge (after just one week of ownership) of selling the BK. Don't get me wrong, it's a lovely sub and produces fantasticly crisp, low bass. But it isnt ported..... ....my old Wharf SW150 was only 150w with a 10" cone. But it was a ported unit so it really shifted the air, creating lovely 'bass' moments to cause room shudder etc in films. The BK is far crisper than the Wharf - and for music it knocks the Wharf into the last century..... but the sealed-box design just doesn't allow the BK to do what the ported Wharf could do with films. At this stage i would love it if someone piped up and said that the BK needs 50+ hours to bed in to become much stronger and offer more shaking bass. But i doubt that is true. Unfortunately my listening style for films is a bit too quiet to allow the BK to shine - whereas at at the same volume levels the Wharf (altho boomy compared to the MUCH sharper BK) was causing things to rattle etc. i.e. it did more for me at those volumes when watching a film than the BK will do. I've tried cranking up the gain a little to 2 o'clock and then pushing the volume up on the amp. The result is a lovely clean, sharp bass - but still not as much room-shudder as the Wharf managed. And at lower volumes its as if the sub is turned off compared to the Wharf, even with more added gain. In a nut-shell i think i have shot myself in the foot, and have become too used to a ported sub for my own good. I love the sound the BK makes, (and i can see why so many people rave about it), but i'm far from happy with the lack of physical bass-hit from it. It just doesn't shake things as well as the ported sub did. I will continue to fiddle with settings, but genuinely think i'm going to be selling the BK very soon to purchase a (better than the old Wharf) ported sub. It may also be that the downward-firing instead of forward-firing cone position isnt helping matters? Dammit! The one plus from this is that a one-week-old BK xls200 in ash black ought to sell for nearly what i paid for it.... unless BK will do a swap for a ported sub of theirs? Do they even sell ported subs...??