x2... the 6 10's will actuay have a little more cone area but not mucha and they can take a little more power...well in theory 6 10's will equal to 4 12's. the twelves will play a little deeper.but not necasarily louder. would be a pretty even match.depending on the amount of power you feed them. imo id say the 6 tens will get a little louder but not really that noticable. only for the fact you can feed more power to 6 woofers rather then 4. if the same woofer. either way you go it would be very loud