RCF ART 708-A MK4 Powered Speaker.In its class, the ART 708-A MK4 is a unique product. The compression driver's 1.0" size provides exceptional vocal clarity and sound projection. An exceptionally linear response and a focused, deep low frequency control are features of the 8" woofer. Modern assembly technologies are used to create the transducers. The 800 watt amplifier is run by a DSP that controls soft limiting, crossover, equalisation, phase control, and speaker protections.