Wow bk12321, I love how you say that and have no other subs to list, and for your info HD3 happens to be pretty loud, I dont know anything though so ask Jeremiah25 on here about his WORLD RECORD in usac sb3 and the subs he used being HD3-12s... as for amps, there are other amps out there what would suit these very well, like say AMERICAN BASS VFL400.1
World record in what class and what sanctaion, the reason for that comment, is because this guy made it seem like the audioque woofers are not loud which is totally un true, as for 450$ a vfl200.1 would fit that price range alot better, would be roughly 1500rms per sub depending your final load
That is not a valid question, it depends on the application, power, vehicle, cd player, battery power, guage wire everything is a factor, with 3000rms, the AQ Hd3 is hard to beat for the price, I would say the Atomic ApX 12, T3 audio TSNS, DD 9512 are all pretty D@MN Loud with 3k