Acoustic couplers; loudspeakers; sub-woofers; amplifiers; sound amplifiers; electronic amplifiers; digital amplifiers; stereo amplifiers; headphone amplifiers; amplifiers for musical instruments; wireless communication apparatus; audio processing apparatus; audio amplifiers; sound mixers; sound level meters; sound recording apparatus; sound reproduction apparatus; sound transmitting apparatus; computer software applications, downloadable; radios; cabinets for loudspeakers; audio mixing consoles; crossovers, being band-pass filters, including active and passive crossovers; headphones; diaphragms, being acoustics; recording discs; sound samplers; dictating machines; electronic audio signal processors for compensating sound distortion in speakers; digital sound processors; downloadable music files; record players; compact disc players; disk drives for computers; DVD players; readers, being data processing equipment; portable media players; optical character readers; megaphones; microphones; sound mixers with integrated amplifiers; analogue sound modifiers; computer programs, being downloadable software; computer operating programs, recorded; computer programmes, being programs, recorded; needles for record players; speed regulators for record players; racks for amplifiers; personal stereos; electrified rails for mounting spot lights; software to control and improve audio equipment sound quality; music-composition software; wireless high frequency transmission instruments; wireless transmitters; sound recording carriers; stands for loudspeaker; tablet computers; horns for loudspeakers; processors, being central processing units; computer peripheral devices; communication interface units