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acoustic feedback

Acoustic Research

Acoustic Research was a Cambridge, Massachusetts-based company that manufactured high-end audio equipment. The brand is now owned by Audiovox. Acoustic Research was well known for the AR-3 series of speaker systems, which used the 12-inch (305 mm) acoustic suspension woofer of the AR-1 with newly designed dome mid-range and high-frequency drivers, which were the first of their kind. AR's line of acoustic suspension speakers were extraordinary for their time, as they were the first loudspeakers with flat response, extended bass, wide dispersion, small size, and reasonable cost.

Company history

Acoustic Research, Inc. (“AR”) was founded in 1952 and incorporated on August 10, 1954 by audio pioneer, writer, inventor, researcher and audio-electronics teacher Edgar Villchur and his student, Henry Kloss. AR was established to produce the $185 model AR-1, a loudspeaker design incorporating the acoustic suspension principle based on patent US No. 2,775,309, granted to Edgar Villchur and assigned to Acoustic Research in 1956.

Technical innovation

Edgar Villchur's technical innovation was based in large part on scientific as well as objective testing and research, making most of it publicly available as documents, specifications, and measurements—all of which was then new in the loudspeaker industry. Acoustic Research, under Villchur's leadership, was also innovative during this period in the way the company offered equal opportunity, liberal employee benefits, insurance, and profit sharing to every employee.

Acoustic suspension loudspeaker

The acoustic suspension woofer provided an elegant solution to the age-old problem of bass distortion in loudspeakers caused by non-linear, mechanical suspensions in conventional loudspeakers. The acoustic suspension woofer (sometimes known as “air suspension”) used the elasticity of air within a small, sealed enclosure of about 1.7 cu. ft. (48 L) to provide the restoring force for the woofer cone. The entrapped air of the sealed-loudspeaker enclosure -— unlike the mechanical springs of conventional speakers—provided a linear spring for the woofer's diaphragm, enabling it to move back and forth great distances (“excursion”) in a linear fashion, a requirement in the reproduction of deep bass tones.

As such, the AR-1 set new standards of low-frequency performance and low distortion that were unsurpassed for many years; in fact, some of the best loudspeakers available fifty-two years later continue to use the acoustic suspension principle for highest quality, low distortion bass reproduction. The small size of the high performance AR-1 (permitted by the acoustic suspension design) was a dividend that helped usher in the age of stereophonic sound reproduction. Two bookshelf-sized loudspeakers were far more acceptable in a living room than the two refrigerator-sized boxes previously necessary to reproduce low frequency bass notes.

By March 1957, AR began shipping a smaller, less expensive, acoustic suspension system, the US$87 Model AR-2. The AR-2 was selected by Consumer Reports as a 'best buy' and the company's sales went from $383,000 in 1956 to nearly $1,000,000 by the end of 1957. Also that year, co-founder and Vice President Henry Kloss left AR (with J A Hofman and Low) to form a new loudspeaker company, KLH.

AR-3

In 1958, AR once again pioneered in loudspeaker technology with the introduction of the landmark model AR-3, which used the AR-1’s acoustic-suspension woofer in conjunction with the first commercially available hemispherical (“dome”) mid-frequency midranges and high-frequency tweeters.

For nearly ten years after its introduction, the AR-3 was widely regarded as the most accurate loudspeaker available at any cost, and was used in countless professional installations, recording studios, and concert halls. Many well-known professional musicians used AR-3 loudspeakers because of their excellent sound reproduction. In the early 1960s, AR conducted a series of over 75 live vs. recorded demonstrations throughout the U.S. in which the sound of a live string quartet (The Fine Arts Quartet) was alternated with echo-free recorded music played through a pair of AR-3s. In this “ultimate” subjective test of audio quality, the listeners were largely unable to detect the switchovers from live to recorded, a strong testament to Acoustic Research audio quality.

The company also established music demonstration rooms on the mezzanine of Grand Central Station in New York City and on Mount Auburn Street in Cambridge, Massachusetts, where the public could stop by and listen to its product, but no sales were made there. This low-key marketing innovation caused a major increase in the company's business.

The AR-3 was subsequently replaced by the AR-3a, with dome midrange and tweeter reduced in dimensions, for even better mid and high frequency dispersion. On September 13, 1993 an AR-3 was placed on permanent display in the Information Age Exhibit of The National Museum of American History at The Smithsonian Institution in Washington, DC.

The AR3a was subsequently replaced by the AR-10pi which had external woofer, midrange, and bass response adjustment switches allowing controls to allow for a variety of room placements. The 10pi had notably even brighter high-frequency response and dispersion than the AR3a.

AR went on to introduce many other notable designs, and by 1966 the company had grown to hold 32.2% of the U.S. domestic loudspeaker market, based on the IHFM and *High Fidelity* surveys statistics for that year. This was the largest product market-share ever held by a loudspeaker manufacturer since statistics have been kept in the industry.

Turntables

AR also produced a low-cost ($78) belt-drive turntable, a type of phonograph, using a cast aluminum 3.3 lb (1.5 kg) turntable platter suspended with a spring-suspended T-bar (sub-chassis) that greatly reduced acoustic feedback. A 24-pole hysteresis-synchronous, permanent magnet Hurst AC motor propelled the platter via a precision ground rubber belt to produce very low wow and flutter, exceeding the NAB (National Association of Broadcasters) standards for turntable measurements.

Many AR turntable models are still sought after today. In particular, the mid-1980s models are highly modifiable to become first-rate vinyl playback units. George Merrill and Anthony Scillia of M/S Research have together designed and refined a series of modifications that bring these units to a level which often exceeds contemporary turntables. A history of George Merrill's contributions to turntable design are available here:

Liquidation

The company went into liquidation in 2004 and the name was bought by Audiovox.

References

External links

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