Im looking for an amp for my XFLs. I had them on an AQ3500.1 @.66. but I had to sell it. They are D4s. So my idea is either find an amp that does 4k ish @.6, 5k @.5, or 2 2.5k amps @1. What ever would be the cheapest way to the most power. looking to stay under 600. Dependng on the amp I might and another sub to run two amps at 1 or 1 big one at .5. So far I have been looking at the older hifonics 5k amps. Let me know what yall think. thank for the input.