I believe Treo makes some of the best gear you can buy. I haven't used any (can't afford it), but there was a local demo vehicle that did. An Excursion with 6 15"s, 3 big amps, the highs and highs amp. I don't know exactly what it was, but it was close to the top. That bass was unbelievable. It blurred my vision standing outside of it.