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In 1956, while a graduate student at MIT, Amar Bose purchased a high end stereo system and was disappointed when it failed to meet his expectations. He later began extensive research aimed at fixing what he saw as fundamental weaknesses plaguing high end audio systems. The principal weakness, in Boses view, was that the overall design of the electronics and speaker failed to account for psychoacoustics, i.e. the listener is part of the system. Eight years later, he started the company, charging it with a mission to achieve Better Sound Through Research which is also the companys slogan.
Research history
During the companys first year in business Bose Corporation engaged
in sponsored research. Its first loudspeaker product, the model 2201, dispersed
22 small mid-range speakers over an eighth of a sphere. It was designed to fit
in the corner of a room, reflecting the speakers sound as a mirror would for
light in a corner cube and giving rise to an acoustical
image of a sphere in a vastly larger room. Amar Bose used an electronic equalizer
to adjust the acoustical output for flat total radiated power.
Although these speaker systems accurately emulated the characteristics of an ideal spherical membrane, the results of listening tests were disappointing some of the reasons for this are detailed in a later publication from Boses research department. This led Bose to conduct further research into psychoacoustics that eventually clarified the importance of a dominance of reflected sound arriving at the head of the listener, a listening condition that is characteristic of live performances. This finding led to a revised speaker design in which eight of nine identical small mid-range drivers (with electronic equalization) were aimed at the wall behind the speaker while one driver was aimed forward, thus ensuring a dominance of reflected over direct sound in home listening spaces, replicating the dominant reflected sound fields listeners experience in live performances.
Before hearing his new design for the first time, although confident that
his new design would produce a more faithful replication of the
"live" listening experience, Amar Bose was unsure as to whether his
new "direct/reflected" design would be a small audible improvement or
a large one over his earlier design and the best commercially available
loudspeakers. The new pentagonal design, named the Model 901, was a very
unconventional design for speakers at the time (which were generally either
full-size floorstanding units or bookshelf
type speakers accompanied by a subwoofer that handled only the very lowest
frequencies). The Model 901 premiered in 1968 and was an immediate commercial
success, and the Bose Corporation grew rapidly during the 1970s.
Amar Bose believes that imperfect knowledge of psychoacoustics limits the
ability to adequately characterize quantitatively any two arbitrary sounds that
are perceived differently, and to adequately characterize and quantify all
aspects of perceived quality. He believes, for example, that distortion is much over-rated as a factor in perceived
quality in the complex sounds that comprise music, noting that a sine wave
and a square
wave (a hugely distorted sine wave) are audibly indistinguishable above 7 kHz. Similarly, he
does not find measurable relevance to perceived quality in other easily
measured parameters of loudspeakers and electronics, and therefore does not
publish those specifications for Bose products. The ultimate test, Bose
insists, is the listeners perception of audible quality (or lack of it) and his
or her own preferences. Unlike other major speaker manufacturers, Bose does not
publish specifications relating to the measured electrical and objective
acoustic performance of its products.. This reluctance to publish information
is due to Boses rejection of these measurements in favour of "more
meaningful measurement and evaluation procedures"
Additionally, the company researches portable audio within the fields of
Circumaural and Supra-aural headphones, centering within the lines of Acoustic Noise Cancellation (see Bose Headphone Family).
