DEQX - Digital audio technology for loudspeaker correction, room acoustics compensation and digital crossover. Solve acoustic problems and improve the sound of any system. Australia. - http://www.deqx.com/
Audio Harmony - Engineering and manufacturing of six channel and two channels harmonic enhancement device. USA. - http://www.audioharmony.com/
Audiodharma - Makes a devices that improved the cable sound quality. USA. - http://www.audioexcellenceaz.com/audiodharmacablecooker.htm
Audiodesksysteme Glass - Makes a CD cleaner and improver. Germany. - http://www.audiodesksysteme.de
Claude Systems Ltd - Supplier and manufacturer of audio enhancement products and induction loops enabling corporate companies to adhere to DDA legislation. - http://www.claudesystems.com
Bedini Electronics - Manufacturers of audio enhancement equipment such as CD clarifier. - http://www.bedini.com/
AudioPrism - Makes products such as power and CD enhancement systems, vibration control, and indoor FM antennas. USA. - http://www.audioprism.com/