i still have some old quad equipment around here. i played around with
it as a youngster and it got me interested in psycho acoustics. this is
the study of how people hear and perceive sounds and the relationship
between hearing and perceiving sound. it turns out that four discreet
channels are no better than an ambience recovery set-up like hafler or
dolby. this is because we only have two ears so direction is determined
by the time lag between sounds registered in opposite ears. the ears (or
rather the brain) is easily fooled by an artificial sound field like
dolby surround sound. the different channels need not be discreet and it
is easier to process and record using encoding or phase cancelling and
recovery techniques. it all can be done with stereo signals and various
schemes like ambience recovery channels or even simple acoustic reflex
tuning of a hall (this gives a surround sound effect from a simple
stereo signal using only the echoes bouncing back from the walls or
baffles in the playback hall) in short quad died because it was
complicated, redundant and a resource wasting format. a equal effect was
obtained easier with the systems in use today. so why did i keep my
quad stuff? maybe as a reminder of my foolish youth.