if you want a real sub, look at eclipse titanium dvc, jl audio w7, diamond xtant series.....these are all top of the line, have friends with each of these sub and they are all HIGH quality...I would say Alpine and Infiniti are about equal....Remember, alot of the quality of sound is determined by many other factors than just the speaker. Try getting a different box, ported maybe, or angled the subs in a different direction....Much cheaper change than buying new components.....Just my $.02