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Rudolph Thomas Bozak (1910–1982) was an audio electronics and acoustics designer and engineer in the field of sound reproduction. His parents were Bohemian Czech immigrants; Rudy was born in Uniontown, Pennsylvania. Bozak studied at Milwaukee School of Engineering; in 1981, the school awarded him an honorary doctorate in engineering. Bozak married Lillian Gilleski; the two had three daughters: Lillian, Mary and Barbara.〔("Rudy T. Bozak: In Memoriam" ). ''Journal of the Audio Engineering Society''. Volume 30, Number 4. April 1982. 'Emory Cook. (PDF) .〕 ==Loudspeakers== Fresh out of college in 1933, Rudy Bozak began working for Allen-Bradley, an electronics manufacturer based in Milwaukee, Wisconsin. Bozak would later employ Allen-Bradley components in his own electronic designs. Bozak moved to the East Coast in 1935 to work for Cinaudagraph out of Stamford, Connecticut. Two years later he was chief engineer. At the 1939 New York World's Fair, a tower topped with a cluster of eight 27" Cinaudagraph loudspeakers in 30" frames with huge 450 lb. field coil magnets covered low frequency duties for a 2-way PA system at Flushing Meadows. The loudspeakers were mounted into horns with 14' wide mouths and were each driven by a 500 watt amplifier derived from a high-power radio broadcast tube. In June 1940, ''Electronics'' magazine published an article that Bozak had written about the design of the 27" loudspeaker. During World War II, Bozak worked with Lincoln Walsh at Dinion Coil Company in Caledonia, New York developing very high voltage power supplies for radar. Bozak joined C.G. Conn in 1944 to help them develop an electronic organ. While in Elkhart, Indiana, he noticed that the human sense of hearing was unpredictable at best. Years later, Bozak recounted this story about the Conn electronic organ project: "The general sales manager, who was a pianist and played organ, sat down and played the thing and said it was great, just what we were looking for. A week later he was invited back into the laboratory and sat down and played the instrument again. He didn’t play ten or fifteen bars when he said, This goddamn thing doesn’t sound right. What did you guys do to it?’ We said we hadn’t done anything. Well, he didn’t believe us. ‘You did something to it. You messed it up here,’ he said. ‘Restore it back to the way you had it.’ So what we did was let the damn instrument sit there for another week, and he comes back and plays it again. ‘Now this is the way it should be,’ he says."〔(''Technology Makes Music: A short, distortion-free history of high fidelity''. ) American Heritage.com. ''Invention & Technology Magazine''. Volume 6, Issue 1. Spring/Summer 1990. David Lander〕 In 1948 Bozak moved his family to North Tonawanda, New York to develop organ loudspeakers for Wurlitzer. While there, Bozak experimented at home in a loudspeaker laboratory he housed in his basement. One design of his featured a kettle drum shell as the loudspeaker enclosure.〔(Kettle drum loudspeaker brochure (1950) )〕 In 1950 Bozak was hired as a consultant by McIntosh Laboratory〔(Feature: McIntosh Laboratory'' ). (PDF) The B.A.S. Speaker. VOLUME 4, NUMBER 9. JUNE 1976.〕 to develop a square loudspeaker driver unit but it was not an engineering success. In 1952 he was making driver units for the McIntosh F100 speaker system. Though these sold reasonably well, McIntosh did not develop the design further. This experience led him to form his own company, Bozak Loudspeakers, in Stamford, Connecticut. Bozak met Emory Cook in the early 1950s; the two hit it off and began working in a shared warehouse basement facility in Stamford. Cook and Bozak thrilled the audio world in 1951 with Cook's ground-breaking stereo recording of train sounds at night: ''Rail Dynamics''. Together, Bozak and Cook implemented a stereo loudspeaker system that would be able to show Cook's stereo recordings to best effect. By the mid-1950s, Bozak had expanded into new quarters at 587 Connecticut Avenue in South Norwalk, with an export office in Hicksville, New York. The foundation of Bozak loudspeaker design was the unique Bozak cone. The woofer cone was molded from a slurry containing paper pulp, lamb's wool and other ingredients in a secret process. The cone was made thicker at the center, becoming progressively thinner toward the periphery. An additional doping of the inner area further strengthened the cone center. The result was a cone with 'variable density' from center to rim with virtually no breakup or standing waves, the major sources of distortion in more conventional paper cones.〔Peter Breuninger. October 2005. ("Bozak Concert Grand B-410 loudspeaker" ). Stereophile. (2005-10-16).〕 The original midrange and tweeter cones were paper. In 1961 the B-209 midrange cone was changed to a radical new design. The material was very thin spun aluminum which took much of its strength from its curvilinear profile along the radius. The cone received a thin coating of latex in order to damp the surface reflections that otherwise would occur on a metal surface which is vibrated rapidly. The design was patented and was largely responsible for the superb transient response of the Bozak B-209B and B-209C midrange. In 1961 the original B-200X paper-cone tweeter re-appeared as the B-200Y, using the same basic cone design of the midrange. The Concert Grand was the crown jewel of Bozak speaker systems since its introduction in 1951.〔Charlie Kittleson. (''CITATION SERIES BY HARMAN KARDON'' ), Vacuum Tube, issue #4.〕 This refrigerator-sized speaker system originally contained four B-199 12" woofers, one 8 Ohm B-209 6" midrange driver and eight tweeters.〔(Hi Fi Lit. Bozak 1956 product literature. JPG image. )〕 The B-310 and B-310A were the mono versions in which the tweeters were arranged as a sector of a sphere for widest distribution of high frequencies. The 'stereo' B-310B and B-400 had the eight tweeters arranged in a vertical row. All Concert Grand models starting from the B-310A contained two 16 Ohm B-209 midrange drivers. The Concert Grand loudspeakers were designed to fill large spaces and were not at their best with listeners closer than 20 feet away. In 1965, a pair of B-410 Concert Grands cost US$2000. Such a high price limited ownership to a small number of hi-fi aficionados and audiophiles. The model line continued to be manufactured by Bozak until 1977.〔 Henry Mancini and Benny Goodman, good friends of Rudy Bozak, owned Concert Grand speaker systems. Jack Webb put a pair in his Mark VII Productions listening room. In 1961, Bozak introduced the B-4000 Symphony. This was sort of "half a Concert Grand," using two 12" woofers, one midrange and the same vertical array of eight tweeters as the Concert Grands. Again, the Symphony was considered to have better imaging than its "big brother" (which was also consider by some listeners to be bass heavy) but was at its best when listeners were no closer than 15 feet.〔 The Symphony was eventually offered in four cabinet styles. The backbone of the Bozak line was the B-302A system, offered in several cabinet styles over a period of years. The 302A systems consisted of one 12" woofer, one midrange driver and one tweeter pair. A 'starter' version, the B-300, was a 2-way system consisting of one 12" woofer and one tweeter pair mounted across the front of the woofer. A single capacitor sufficed as the crossover 'network' for the B-300. The system could be expanded to a 3-way B-302A by adding a midrange and full 3-way Bozak crossover. Acoustic suspension arrived in the loudspeaker marketplace in 1955, making it possible to get low bass from a small, bookshelf-sized enclosure. This seriously affected the sales of "big box" speaker systems of all brands. Rudy Bozak never offered an acoustic suspension speaker system; he stated that the full transient response and clean bass for which his woofers were famous could not be obtained with the heavier, reinforced woofer cones necessary for acoustic suspension. Bozak began offering smaller speaker systems to answer consumer demand, but none were noted for exceptional performance until the LS-200 and LS-200A of the late 1970s. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Rudy Bozak」の詳細全文を読む スポンサード リンク
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