QSound is the original name for a positional three-dimensional (3D) sound processing algorithm from QSound Labs that creates 3D audio effects from multiple monophonic sources and sums the outputs to two channels for presentation over regular stereo speakers. QSound was eventually re-dubbed "Q1" after the introduction of "Q2", a positional 3D algorithm for headphones. When multi-speaker surround system support was later added to the positional 3D process, the QSound positional 3D audio process became known simply as "Q3D". QSound was founded by Larry Ryckman (CEO), Danny Lowe and John Lees. Jimmy Iovine served as SVP of Music and Shelly Yakus as VP of Audio Engineering in its formative years. Technology QSound is essentially a filtering algorithm. It manipulates timing, amplitude, and frequency response to produce a binaural image. Systems like QSound rely on the fact that a sound arriving from one side of the listener will reach one ear before the other and that when it reaches the furthest ear, it is lower in amplitude and spectrally altered due to obstruction by the head. However, the ideal algorithm was arrived at empirically, with parameters adjusted according to the outcomes of many listening tests. 3D positional processing like QSound, the multi-channel QSystem professional processor used in the production of pop music and film audio, is distinct from stereo expansion like QSound QXpander or SRS(R) Sound Retrieval System. Positional 3D audio processing is a producer-side technology. It is applied to individual instruments or sound effects, and is therefore only usable at the mixing phase of music and soundtrack production, or under realtime control of game audio mixing software. Stereo expansion (processing of recorded channels and background ambience) is primarily a playback process that can be arbitrarily applied to stereo content in the end-user environment using analog integrated circuits or digital signal processing (DSP) routines. Adoption The system was used in all Capcom CP System Dash, CP System II titles and the Sony ZN-1 and ZN-2 hardware arcade games such as Battle Arena Toshinden 2. QSound was utilized on Madonna's 1990 album, The Immaculate Collection, Sting's 1991 album, The Soul Cages, Luther Vandross's 1991 album, Power of Love, Paula Abdul's 1991 album, Spellbound, and Roger Waters's 1992 album Amused To Death. Electronic Arts, Activision, Microsoft Game Studios, Sega, Virgin Interactive, TDK Mediactive, Bullfrog Productions, and Lionhead Studios have also used the technology, mostly through the use of the QMixer software development kit to