Hi, so my buddy has a Rockford Fosgate TRF2215 subwoofer. He wanted to get a Hifonics Colossus as a final stage. I told him then that there are probably even better final stages in the price range. I then looked for it myself, but somehow found nothing suitable. The impedance (Dual 1.4Ohm) makes me a few problems. In row the resistance is too high and in parallel again too small for most final stages. I think so 2000Watt RMS should already be at Woofer already Does it make sense to give both coils an extra level, or rather one? Which power amplifier can you recommend? Its Budged is between 1500 and 1600€.