they're not the greatest thing, they're kinda budget brand, i'd only consider their HIGH END stuff, but they're considered a questionable brand. Do you have the specs of the amp?
forget about max power, that's never real. Your amp should be putting like 600w rms at 1 ohm (cuz planet audio is overrated). If those subs are dual 4 ohm you should consider buying hifonics 1606d if you're on budget. Try selling the planet audio. By the way, those subs are SPL only, no SQ at all.