RCF ART 745-A MK4 Powered Speaker.The top speake r in its class is the ART 745-A MK4. The 4.0" voice coil neodymium compression driver with a titanium dome gives exceptional vocal clarity and sound projection. Neodymium 15" woofer provides a precise, deep low frequency control and an incredibly linear response. Modern assembly technologies are used to create the transducers. The DSP that controls the amplifier's 1400 watts of power handles the crossover, equalisation, phase control, soft limiting, and speaker protections.