D20 The system should consist of a passively separated 3-way loudspeaker cabinet, which is driven and protected by a special controller output stage. The loudspeaker should contain a 12" loudspeaker for the low frequency range and an 8" loudspeaker for the medium frequency range in a bass reflex tuned cabinet. The used loudspeakers should be impregnated weatherproof. In the high frequency range, a pressure chamber driver with a 1.75-inch ring diaphragm is to be used, which is located in a coaxial arrangement with the 8" low centre loudspeaker. The pressure chamber drivers used should be coupled to a symmetric horn with a 90° beam angle. The continuous load capacity of the system should be 1,000 watts RMS. The loudspeaker should have a nominal impedance of 4 Ohm. The usable system bandwidth should be 35 Hertz to 20,000 Hertz (-4 dB). The maximum peak sound pressure level should be 133 dB, measured with pink noise at a distance of 1 m, under half-space conditions and with a crest factor of 6. The loudspeaker cabinet should be made of birch multiplex and sealed with a weather- and moisture-resistant polyurea coating (PU). The front of the loudspeaker should be equipped with a ball-proof protective grille, which is backed with acoustically neutral foam. Its physical dimensions should be 342 mm in width, 700 mm in height and 425 mm in depth. The weight of the loudspeaker shall be 26 kg. The loudspeaker should have M6 mounting points with which special accessories can be mounted. It should be possible to mount the loudspeaker box on a stand flange using accessories. With optional flying brackets the loudspeaker box can be mounted in horizontal and vertical alignment. The system should be available in left and right speaker versions. The loudspeaker should be connected via two 4-pole SpeakON sockets. The manufacturer's warranty shall be 5 years.