RCF ART 712-A MK4 Powered Speaker.In its class, the ART 712-A MK4 is a unique product. The professional compression driver offers exceptional vocal clarity and sound projection thanks to its custom-designed dome and high power voice coil. A precise, deep low frequency control and an incredibly linear response are features of the 12" woofer. Modern assembly technologies are used to create the transducers. The DSP that manages crossover, equalisation, phase control, soft limiting, and speaker safeguards controls the 1400 watt amplifier.