The last few years I have done SEMA and the CES show and each time somehow our booth is always next to or very close to Earthquake. This last year I listened to some demo cars and I was very impressed. They even had an amp that was rated 20,000 watts RMS and from the size of it I believe it. You should check them out, I can't imagine a more clean power for the price.
I got maximum excursion on my W3's. I actually popped off a dust cap on one and had to have it re-glued. The box was CAD designed to fit in the ackward space of a 3rd gen Firebird and airspace was correct. There was a big difference between 1st and 2nd gen HiFonics amps...I actually got the amps from an SPL champion car when you could not find them anymore. I used to push Lanzar Pros back when Lanzer used to be good, but just like HiFonics they turned into a cheap low quality brand in later years.