B5 can be easily operated using the Systemcontroller K&F CD 44 with the mid-high range system. Both of the B5's 18” drivers affect one separate vented chamber. Both cones jointly affect the 3rd pressure chamber, which is open on the front. In doing so, an enormous increase in efficiency and high rear attenuation of the total system is achieved. The K&F ACCESS Series is a high-performance PA system which does an outstanding job of living up to all demands ranging from hard rock to classical. With a uniform dispersion pattern, the K&F ACCESS Series is suitable for small and mid-range PA systems which already have just one system (top + sub) per side. The set-up of several K&F ACCESS Systems to form pair clusters or large arrays increases the flexibility for various uses ranging up to large PA systems.