The Pioneer P.R.O. (Pioneer Reference for Open Show) series of speakers is designed specifically for those looking to produce serious sound pressure levels. Inspired by Pioneer’s history of record-breaking SPL competition, the new P.R.O. Series line of speakers is constructed with the street enthusiast in mind. Emphasizing efficiency and power handling, the P.R.O. series lineup consists of bullet tweeters, mid-bass drivers, and a subwoofer that can be mixed and matched to deliver impressive output without requiring a significant investment.