Anyone used or even tried any of the K2 Power series subwoofers?

Wondering how they are for SQ and range.

Right now I have 2 AVI SLS-300 and they are excellent drivers but I will be building a completely new system over the winter months and wanting input.

I was also considering the Alpine typeX 12" or maybe the Zapco line.
Normally I just add sub bass to enhance, but I do like a subwoofer that can loosen your eyeteeth (hard hitting) but also musical, so take it from there.

Thanks

ps: suggestions......

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Active system - Eclipse cd7000 - Focal k2p - Audison LRx 4.1k and Audison LRx1.1k - AVI sls300 x 2 in custom built spare tire well enclosure