Alpine R-A90S R-Series 6/5/4/3 Channel Power Amplifier - Experience your music in Hi-Res with the versatile R-A90S 6-Channel Amplifier for hair-raising details that puts you in the center of the performance. The R-A90S features a staggered power channel layout that allows each channel to host different levels of power, compared to traditional, multi-channel amplifiers. This allows the R-A90S to effectively function as both a 3-way active amplifier and a 5-channel amplifier by delivering the power you need to the channels where you need it the most. Hear the subtle details you’ve been missing in your music with the R-A90S. With the highest power output in its category, the R-A90S drives power to your sound system to create a big dynamic music range for the listener, reproducing high-frequency sounds up to 45k Hz, making the R-A90S Hi-Res Audio Compliant. Alpine’s R-Series line of speakers, subwoofers, and amplifiers have a heritage of sound quality that can be heard from a block away. The R-A90S is tuned to emphasize the characteristics of the R-Series speakers and subwoofers for a legendary R-Series experience. Technical Specifications - • Hi-Resolution Audio Compliant (40k Hz) • CTA-2006 • Alpine’s Class D Amplifier Circuit • 75W x 4 + 150W x 2 (4Ω, 14.4V, Less Than 1% THD +N) • 100W x 4 + 250W x 2 (2Ω, 14.4V, Less Than 1% THD +N) Alpine RUX-H01 Remote Bass Knob for the Alpine Halo Display - • Remote Bass Knob for the Alpine Halo Display • Fits the iLX-F259, iLX-F309, and iLX-F411 9-inch and 11-inch screen • Compatible with the X-A90M, X-A90V, R-A90S, R-A75M, R-A60M, S-A55V, PDX-V9, KTA-200M • Also compatible with the X-A70F, R-A60F, S-A32F in 3-channel mode for level control on channel 3 or 4 when bridged