Bose Stereo

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During the companys first year in business the 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^[1] 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.^[2] Unlike other major speaker manufacturers, Bose does not publish specifications relating to the measured electrical and objective acoustic performance of its products.^{[3] [4]}. This reluctance to publish information is due to Boses rejection of these measurements in favour of "more meaningful measurement and evaluation procedures"^[5].

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.

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). 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. Also, unlike full-sized floorstanding units, the speakers use a special floorstanding pedestal to raise them. The pedestal design is a metal tube with a large base on the bottom and a smaller speaker support base at the top. This design helps the speakers perform at their full potential.

 Specifications/Features

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

 Timeline

Bose Acoustimass 5 Series I (1987)

List of stereo speakers from Bose:

• 1966 - The Bose 2201 (only year sold)
• 1968 - 901 Series I (until 1973)
• 1971 - Model 501 (until 1977)
• 1973 - 901 Series II (until 1976)
• 1975 - Model 301 (until 1983)
• 1976 - 901 Series III (until 1978)
• 1977
• 501 Series II (until 1980)
• 601 Series I (until 1982)
• 1978 - 901 Series IV (until 1983)
• 1980 - 501 Series III (until 1984)
• 1982
• 201 Series I (only year sold)
• 601 Series II (until 1986)
• 1983
• 301 Series II (until 1991)
• 901 Series V (until 1987)
• 1984
• 101 Music Monitor system (until 1997)
• Model 121 (until 1994)
• Model 141 (until 2003)
• Model 171 (until 1994)
• 201 Series II (until 1991)
• 501 Series IV (until 1994)
• 1985 - 8.2 (until 1988)
• 1986
• 4.2 (until 1992)
• 6.2 (until 1994)
• 10.2 (until 1998)
• 601 Series III (until 1994)
• 1987
• 2.2 (until 1992)
• 901 Series VI
• Acoustimass 5 Series I (until 1990)
• 1988
• 10.2 Series II (until 1994)
• 401 (until 1994)
• Acoustimass SE 5 (until 1991)
• 1989
• Acoustimass 3 Series I (until 1990)
• RoomMate II powered speaker system (until 1999)
• 101 Italiano (Freestyle) speaker system (only year sold)
• 1990
• Acoustimass 3 Series II (until 1994)
• Acoustimass 5 Series II (until 1998)
• Acoustimass powered speaker system (until 1993)
• 1991
• 201 Series III (until 1996)
• 301 Series III (until 1996)
• Powered Acoustimass 3 (until 1994)
• Acoustimass SE 5 Series II (until 1994)
• 1992
• 2.2 Series II (until 1996)
• 4.2 Series II (until 1996)
• VS-100 (until 1995)
• 1993
• Acoustimass 4 home theater speaker system (until 1998)
• Powered Acoustimass 5 Series II (until 1995)
• 1994
• Model 100 speakers (until 2001)
• 151 environmental speakers (until 2005)
• 501 Series V (until 2001)
• 701 Series I ^[6] (until 2001)
• 2001 (until 1998)
• 4001 (until 1998)
• Acoustimass 3 Series III (until 2000)
• Powered Acoustimass 3 Series II (until 1999)
• 1995
• V-100 (until 1998)
• V-300 (until 1997)
• AM-500 Acoustimass (until 1998)
• 1996
• 201 Series IV (until 2002)
• 301 Series IV (until 2002)
• 1997
• 101 Series II Music Monitor (until 2001)
• 131 marine speaker system
• VCS-10 center speaker
• 1998
• 10.2 Series II (until 2001)
• Model 100 J Speakers (until 2001)
• 301 AVM limited edition speakers [301 Sonata] (only year sold)
• Acoustimass 5 Series III
• 2000
• Model 111 outdoor loudspeaker (until 2001)
• 251 environmental speakers
• Acoustimass 3 Series IV
• 2001
• 161
• 601 Series IV (until 2004)
• 701 Series II (until 2003)
• FreeSpace 360P environmental speakers (until 2003)
• 2002
• 201 Series V
• 301 Series V
• 2003
• Virtually Invisible 191 speakers
• FreeSpace 51 environmental speakers
• 2004 - 151 SE environmental speakers
• 2005 - Lifestyle RoomMate
• 2006- SoundDock