Bose stereo speakers

Bose has been a manufacturer of stereo speakers since the late 1960s. The company produces a wide range of stereo speakers.

Overview

During the company's first year in business the Bose Corporation engaged in sponsored research.^[1] 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 speaker's 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.^[2] Amar Bose used an electronic equalizer to adjust the acoustical output for flat total radiated power.^[3][4][5][6]

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^[7] from Bose's 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.^[5][8]

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). The Model 901 premiered in 1968 and was an immediate commercial success, and the Bose Corporation grew rapidly during the 1970s.^[3]

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 listener's perception of audible quality (or lack of it) and his or her own preferences.^{[9] [10]} This reluctance to publish information is due to Bose's rejection of these measurements in favour of "more meaningful measurement and evaluation procedures".^[11]

Bose 901 speakers

The Bose 901 Speaker System is a speaker system originally created in 1968. The speakers were a huge success for Bose making it grow rapidly throughout the 1970s. The speakers are a company hallmark for Bose.^[3][5]

Design

When the speakers were released in 1968, they featured a pentagonal design which was very unconventional at the time (many of the speakers at the time were either full-size floorstanding units or bookshelf speakers). This design helps the speakers use "Direct/Reflecting" technology that uses the walls and ceiling around it to distribute sound throughout a room (like in a live performance).^[5][8] To do this the speaker has eight Full-range drivers in the back and one in the front. The "Direct/Reflecting" technology is designed to reproduce the acoustics of a live performance on stereo speakers, however, studio recordings may sound the same as they do on conventional speakers.^[3][5][8]

Specifications/Features

• Nine Full-Range Drivers – One direct firing speaker and eight rear firing speakers.^{[3][4][5][6][8]}
• Active Equalizer – The speaker set includes an equalizer made specifically for the speakers. This controls frequency outputs to the speakers.^[3][4][5][6]
• A special Acoustic Matrix Enclosure – This helps reduce speaker chamber noise and to help hear well-defined low frequencies over the low-frequency spectrum.^[5][6]
• Helically-Wound Aluminum Voice Coils – These are designed for high durability, greater efficiency and superior power handling.^[5]

Review

Bose's flagship 901 speaker system was criticized by Stereophile magazine in 1979.^[12] In a review of the 901 system, stating that in the magazine's opinion, the system was unexceptional and unlikely to appeal to perfectionists with a developed taste in precise imaging, detail, and timbre; and that these shortcomings were an excessive price to pay for the improvement in impact and ambiance generated by the large proportion of reflected sound [to on-axis sound]. However, the author also stated that the system produced a more realistic resemblance of natural ambiance than any other speaker system.

Timeline of Bose stereo speakers

References

• Stereophile review of the Bose 901
• Bose.com 901 information