They were used, and being run by a 350W RMS x 2 Kicker amp (old school Kicker amp lol), also used.
The install was done by a local shop the sells Kicker and Memphis. Although that hooked my subs up at 8 ohms to the amp...(Had to rewire to 2 ohms, since I had each sub running at 4 ohms). That was when I had my Volfenhags though.
i new a guy with 1200rms the big infintiy mono amp (well according to infinity) an he ran 2 kappa perfect 10's for a while it sounded great(except tweeter gave him double sub box and didnt make a wall...idiots it sound terrible turned up)anyway he messed on up when the tensile leads burned off...im am gonna buy both of them for 50$ 1 works fine the other...well can be fixed...cant wait till i get em