AES members report on ASSG Billy Woodman event.
Several members of the AES accepted the ASSG invitation and attended their recent Billy Woodman (ATC) presentation on his latest loudspeaker design work.
Here, courtesy of committee member Graeme Huon, is a report on this event.
Two old friends and pioneers of the world audio industry met in Melbourne on 21st January 2014. Billy Woodman, Australian, and founder of The UK. pro and hifi loudspeaker company ATC visiting Australia met with Mike Barabasz, founder of Melbourne Pro and HiFi woofer manufacturing company Lorantz. The occasion was the demonstration of the ATC SCM25A three way active loudspeakers organised by Peter Orehov of CDA pro audio Sydney through the ASSC and was held at Black Pearl Studios in Moorabbin. These speakers feature Billy’s dome midrange driver of world renown for on- and off-axis response and lack of colouration. They sounded excellent in direct comparison with live miked piano in the studio next door.
Billy, a long time musician and respected piano player strongly advises live piano and voice as the reference for loudspeaker evaluation. “We certainly should know what that sounds like, and when it sounds wrong – though there might be quite a lot of engineering required to get it right!” he said. To Billy, headroom for dynamic transients without clipping, crushing and other distortions is very important, particularly with the dynamics of the piano. This certainly applies to amplifiers, but headroom in the loudspeaker drivers themselves is equally important. But in the end, audition by trained listeners will always be necessary to uncover any missed issues before a new design is production-ready. Then the only remaining challenge is to have a stable production process able to produce consistent product.
Billy and Mike originally worked together at Plessey in Melbourne manufacturing loudspeakers before each launched their own companies. They are long term supporters of AES and professional engineers through and through. Topics discussed ranged from the fundamental engineering requirements for drivers with high efficiency, controlled directivity, flat frequency response and minimal distortion colouration, to crossovers and even to component supply continuity issues for sustained high performance amplifier manufacture which is becoming a major issue in this digital age.
Sound Engineering is their passion. When asked, both Mike and Billy acknowledged MC Lachlan’s 1956 book on Ordinary non-linear differential equations (in engineering and Physical science) as a pivotal influence in their work, conceding that in part this was because the non-linear device used as an example in the text was the loudspeaker!
Billy discusses amplifier design for performance with AES Melbourne committee member Julian Driscoll.