their single 4 ohm so 4+4 = 2 ohm load or 8 ohm final load.
need an amp that does power at either of those. Rockford Fosgate Prime 500.1 can be had for what you're looking to spend and they put out a tad more than rated. I got one on here in mint condition for 90 shipped actually does 520-540 if I remember, i'll check the sheet later. does power @ 2 ohm though which is what you'd need.