i got 2 mtx 7500 subs with one 421d amp running it and itll shake ppls houses when i drive down my street. i want another 421d tho. theres an audio place next to where i work and just from listening there the best stuff for speakers/headunit in my opinion is the kenwood excelon(sure thats spelled wrong) stuff. there componet speakers are like 350 bucks but sound absoulutly amazing. i also have a jvc head unit...the exad model with the touch screen and i like it alot..its got a lot of flexibilty on altering ur system. but as far as subs go i think mtx all the way.