Hi guys. I need your advice.

My situation: I currently have a pair of K2-9800SE (which I love) - for stereo purposes only. I use a Klipsch THX2 Ultra 7.1 System in my HT ATM. I would like to sell the Klipsch, buy a SK2-1000 Center and build up a full 7.1 Synthesis system.

My question is regarding the S1S-EX subwoofers. I would run them with matching JBL S800 monoblocks.

What do I want: The meanest, most powerful, spectacular, deepest and all around frightening bass money can buy - I think you get the point. Restrictions: I don't want to build it myself (if thats what some of you DIY guys where going to suggest), Initially I'm going to use at least 2, further down the road 4 subs, I'm not on a strict budget BUT I want the most bang for the buck - and I mean BANG!

So on to my question: How does a S1S-EX/S800 combo compare to "alternatives" like SVS Ultra/2, Velodyne DD18/DD1812, Klipsch THX Ultra2 KW120, ... ??? I like my Klipsch but want MORE. I have heard DD18 but they are too "gentle" for my liking. I want something "violent, brute". Super high potential SPL, low distortions. But it should be able to dig really deep (usable 16Hz-18Hz output) at the same time.

Where to look for something like that? Are there any subs out there that are comparable/competitive considering what I want bass to sound - "fierceful" ? Thanks in advance for your opinions.