The Buzz: 20 Years Ago in Sound & Video Contractor

Power to the Speakers!
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The Buzz: 20 Years Ago in Sound & Video Contractor

Mar 1, 2005 3:06 PM

Power to the Speakers!

Ok, so the old rallying cry from the ‘70s is a bit modified. The March 1985 issue focused on power amps. Leading off was “Power Amplifiers: Design and Selection” by Cal Perkins. Back then Perkins was an amplifier design consultant as well as a member of the Sound & Video Contractor consultant staff. Nowadays Perkins works for Mackie, most recently developing the EQ section of their new Onyx series of mixers. William H. Isenberg, also a member of the Sound & Video Contractor consultant staff, provided guidelines for selecting an amplifier that best suited the readers’ requirements in “Choosing an Amp.” Isenberg was a circuit design consultant affiliated with Marshall Long Acoustics.

Continuing in the amplifier vein, Harry E. Klaus discussed “MOSFET Technology” in amplifier design. Klaus was director of engineering for the David Hafler Company.

On the business side of things, Penny Weigand looked at “The Legal Aspects of Leasing” reflecting an increased interest in considering equipment leasing as an alternative to purchasing and Robert H. Jerry II explained some of the contractual obligations that might be encountered as a subcontractor in “Subcontracting: Some Trouble Spots.”

Thomas Danley, then an electro-acoustics researcher with Intersonics provided a Technology update: “Motor-driven Revolution”, which took a look into the technology of the Servo Drive loudspeakers. After many years at Servo Drive, Danley left the company in late 2004.

James Tawney profiled the microphone system renovation of the West Virginia Senate Committee on the judiciary meeting room in “Custom Communications.” The install utilized a Shure automatic microphone system and Dukane amplifiers and speakers.

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Another technology update, “A New Approach to Power Handling,” was provided by Harro K Heinz and William Gelow, president and chief engineer, respectively, for Renkus-Heinz. In the article, Heinz and Gelow discuss their application of smart control electronics for loudspeaker system protection. Currently, Heinz remains president of the organization. While with JBL in 2002, Gelow received a Technical Achievement Award with Bernard Werner for the engineering and design of Filtered Array Technology and Screen Spreading Compensation as applied to motion picture loudspeaker systems from the Academy of Motion Picture Arts and Sciences. Gelow is no longer with JBL.

“Reinforced Audio,” a new column by David Schierman was presented as a forum to discuss new technologies for sound reinforcement as well as provide information on operating techniques. Schierman was president of Concert Sound Consultants. Currently, he is director of tour sound for JBL Professional.

A look at some of the ads in the issue: Switchcraft promoted its new printed circuit jackfields. Industrial Research Products introduced the Model DH 4020 Power Amp, a dual 100W per channel MOSFET amplifier. One rack space and ten pounds! And Bogen featured their telephone paging systems along with their new individually amplified speakers.

Business News reported that White Instruments had been purchased by Carl Van Ryswyk, formerly the vice president of engineering for the company. White produced a well-known line of equalizers and analyzers. In 1996 Van Ryswyk sold White Instruments but remained a consultant to the company. In 2002 Van Ryswyk repurchased the assets of White. Also, AKG Acoustics took over U.S. distribution of its products by establishing a wholly owned subsidiary in Stamford, Conn.

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