The R-series bookshelf is a culmination of S-series patented technology with materials developed from the ground up in every part of the design just like it’s big brothers. The R4b can be the heart of any 2.1 system, LCR for a small theater, or Surrounds using a complete no holds barred R-series system. Silky smooth, loads of dynamic range, and great transient response. Hallmarks of a PERLISTEN speaker.