Polk Audio RM201 Satellite Speaker (Single, Black) Single satellite speaker for the RM series 6.1 or 7.1 channel speaker system Equipped with dual 3.25-inch mineral filled polymer composite midrange drivers Frequency response: 95 Hz - 24 kHz Equipped with a single 0.75-inch silk/polymer composite dome tweeter Bolt-on swivel wall-mounting brackets with hidden wire channels