Quadraphonic

Most of those responsible for the European development of the Quadraphonic stereo system would probably rather forget that they were involved. To say that it was a dismal failure would be kind, to say that it was an absolute sales stinker would be fair, but to say that it didn't work would be wrong.

The quadraphonic stereo system achieved its unique 'surround sound' via the use of four independent sound channels - usually two front and two rear speakers. The actual records were encoded in such a way that the music could be recorded in two stereo channels.

In order to actually get four channels and not just two, the reverse decoding process had to take place during playback, requiring an additional amplifier and (of course) two more speakers.

The main problem was that 90% of those who purchased a quadraphonic-capable stereo never bothered to invest in the extra bits and pieces they needed to make it work in true quadraphonic. The result though was almost unperceivable to most listeners over conventional two-channel stereos.

When you combine these problems with the fact that there were three different, and incompatible, decoding systems on the market at the same time and it's no surprise that the idea sunk without a trace.