What are your thoughts on the "Edsels" of the audio history?


It is a human normal to seek the best, and the world of the high end audio fan is full of that history.  But what about some of the dead-ends/failures?

How about Quadraphonic, Perfect Sound Forever, 8-track tapes, SQ and others in your thoughts/memory? 





whatjd
The Hill Plasmatronic Loudspeakers. I helped set up a pair. My first inclination was, you'd have to be out of your mind! 
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The Terk “pi”, fm antenna was such an Edsel IMO. It may have performed well right in the middle of big cities...I wouldn’t know as I lived 30-ish miles out and got much better use out of a big TV type aerial on my apartment ceiling. To the best of my memory, the little round disc was supposed to be “revolutionary” though and they certainly got this 20-something’s (at the time) eighty bucks...