If I had to pick on, it'd be Alpine. RF is too boomy for me, sort of a distorted kind bass, it just sounds so flat. But then again, it could have been the box it was playing in. Any of these subs can be good, with the right model sub, the right amplification and the right box... anyone of these can sound better then the other. 90% of car audio is install, the rest is the equipment and the tuning of it. Speaker placement and enclosure size has everything to do with the way it will sound when it gets to your ears.