10. Sansui Quadraphonic Sound
Starting with 1972, Sansui made it possible for home users to enjoy the experience of a four-channel home audio system, that record companies and musicians had been working with since the early 1960s, by introducing its quadraphonic amplifier, the QS-1.
The price was $200 or $1,200 in today’s money.
Record labels also helped spread the use of quadraphonic sound, as did well-known bands, including Aerosmith and the Eagles, that released albums for four-channel stereo.
However, not everyone was happily ready to spend money on a new receiver and two extra speakers So, after 6 years, the production of QS-1 was stopped, and the music industry discovered digital recording and moved on.