I've used a MA audio 10" qs ($50 sub) and a 12" HK12D4($200 sub) neiter got super loud but the HK12D4 wasn't too bad with loudness or Sq. There are deffinitly a lot better sub choices for 200 bucks though. I bought 2 kicker comp 15" for 120bucks total to try out my dual 15 box and they bang pretty hard.