ive heard some really hight end ones, they put out good mid-bass but not a lot better than my 15$ pioneers tho (the kickers cost about 250$) yea, my friend is jealous, owell his mommy and daddy bought him a 600$ kenwood hu (without even rotary volume!) and the kickers, and i like my hu and 6x9s much better and i paid under 200 $ total, and his mommy paid over 800$ for his shitty system!!!