Apparatus for recording, transmission or reproduction of sound and/or images, in particular mobile and/or fixed loudspeaker systems and/or video systems, and accessories therefor as far as included in this class; computers for controlling the aforesaid apparatus; computer software for controlling the aforesaid apparatus; in particular computer software for implementing wave field synthesis for reproducing sound.

Installation, maintenance and repair of apparatus for recording, transmission or reproduction of sound and/or images and computer hardware relating thereto, in particular installation, maintenance and repair of sound and/or image reproduction apparatus for exhibition halls, exhibition stands, concert halls, cinemas, urban facilities, appartements, ships, buses, aircraft, motor vehicles, railway stations, airports, sports stadiums.