Another vote for BK. I've got the XLS300-FF and it's a great sub, goes low enough to pump vibrations through you. I went for a Grade "B" from their eBay store and it arrived completely mint for £338.86 + £10 postage.
Mine is a similar size room, 21.5m², with the volume being 64.5m³ (3m ceilings) and I'm only running it at around half power. I was also considering the SVS SB-1000 Pro, which PT have in at a discounted £549 at the moment, but it's hard to beat the XLS300 where you can save £200.
Update on thread, just ordered the same deal as yours above, Grade B from the Ebay BK shop, XLS300-FF on the way, can't wait.
You're gonna love it!
Sub now arrived, BK were pretty slow on dispatch even though it was from the Ebay store, can't see any reason why it is a grade B, absolutely mint condition, so very happy.
Got the settings all dialed in and it sounds immense, certainly powerful enough for the room size and I'd say I've got it running at about 50 to 60 percent, goes nice and deep and has married up with the other channels really well.
I give it 6 weeks before you order anotherSub now arrived, BK were pretty slow on dispatch even though it was from the Ebay store, can't see any reason why it is a grade B, absolutely mint condition, so very happy.
Got the settings all dialed in and it sounds immense, certainly powerful enough for the room size and I'd say I've got it running at about 50 to 60 percent, goes nice and deep and has married up with the other channels really well.