Loudspeakers; Analogue to digital converters; Audio amplifiers; Audio interfaces; Audiovisual receivers; Card reading equipment; Central processing units (CPU); Computer memory devices; Computer network hubs; Computer network switches; Computer terminals; Data processing equipment, namely, couplers; Data synchronization cables; Digital signal processors; Downloadable music-composition software; Electrical amplifiers for use with musical instruments; Electronic switchers for audio and video si...