Quadraphonic sound uses four channels in which speakers are positioned at all four corners of the listening space, making it very confusing for any poor pets or small children who wander into the room.
Quadraphonic sound was one of the earliest consumer offerings in surround sound. Introduced to the American market in September 1970 as the Quad-8 / Quadraphonic 8-Track. Quad (as it became known) didn't remain restricted to one format, but was later a myriad of different and largely incompatible formats on different media: quadraphonic could be obtained from vinyl records, eight tracks, and reel-to-reel. There were even some experiments with radio broadcasts, for example a Cliff Richard concert by the BBC, although he has outlived the format by many a year.
With speakers in the middle of doorways and unsightly black wiring over the floor there was no way the Quadraphonic sound system would last.
"Quad", in its original form, was a commercial failure, and the LP formats were plagued with technical problems that were solved too late to save the system from a consumer point of view. The format was more expensive and required extra speakers, which became a problem as people in the 1970s were not willing to re-model their chic homes and apartments just so they could experience Prog Rock and Easy Listening music from all directions. Imagine having to group all your furniture in the centre of the room, it was a decorating nightmare!
However, quite a few recordings were made before its demise, many of which have been dredged out of the archives for opportunistic re-release as 5.1 surround sound dvd's. Time will tell if the pets of today fair any better than those in the 70s.