Alpine R2-A75M Amplifier 1 Channel Monoblock Subwoofer Class D Upto 750w RMSAlpine R Series Amps: Born to be Played Loud R Series Mono Power Amplifier RMS Power Ratings 1 x 750W @ 2 Ohms R2 A75M The Alpine R Series line of speakers, subwoofers and amplifiers have a heritage of sound quality you can hear from a block away, and the newly added R Series amplifiers are no exception. Aside from their best in class performance, these amplifiers are tuned to emphasize the characteristics of the R Series speakers and subwoofers,