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6:30 pm Pizza and Beverages compliments of White Radio Limited
Shuttle Pick-up is available from APPELBY GO STATION:
Contact Phyllis 798-7959 (Toronto number) to Pre-Arrange Pick-up.
Contact GO Transit for time schedule 665-0022.
7:30 pm Mr Bruce Howze, Owner and Chief Design Engineer of Community
Loudspeakers will be presenting and discussing design parameters of
Community Products including low compression drivers,
electronically controlled loudspeaker systems, and their new product, a
loudspeaker with 6 x 6 x 7 foot dimensions, 2400 watt power handling
and capable of producing 136 dB.
What's Inside
This Month's Meeting
PreviewBruce Howze and the Community Loudspeaker
This month's guest speaker, Bruce Howze has been associated with what is known as the professional sound industry since its very beginning. His pioneering use of innovative materials, his penchant for no-nonsense design and a strong belief in giving value for money have earned him and his company, Community Professional Sound Systems, a customer base of fans throughout the world.
Bruce is an influential force in midrange driver design. Wherever possible, his system designs for Community are three-way, with special attention paid to that part of the musical spectrum where most music and human voice lies. As a loudspeaker designer, he is highly regarded... whether the need is for a powerful midrange driver for large stadium systems, or a specialized driver for voice-warning which can generate intelligible speech over a distance of two miles.
Recently, Community celebrated their 25th year in the professional sound industry. Their current product line includes over forty items and is marketed to musicians, contractors and touring professionals.
Last Month's Meeting
Review
On October 12, the AES Toronto Section was host to Rupert Neve at a meeting held at Film
House's Adelaide Street East Theatre 1 studio. Mr. Neve is the classic example of the man who needs no introduction: he has been a force in recording console design for almost 30 years and has designed some of the most sought after "classic" consoles.
Mr. Neve began his talk with a review of the philosophical underpinnings of the search for audio perfection. This is an area rarely examined by many in audio, yet it is the source of the values by which the quality of music and audio apparatus are judged. This theme was expanded upon and related to many common definitions of audio quality and in particular to Mr. Neve's approach to critical evaluation of his designs. In particular he spoke of the desirability of equipment performance limits beyond the generally accepted limits of human perception.
The desirability of wide bandwidth, low distortion design was illustrated by both logic and anecdotal evidence. The often overlooked detail of the spectral distribution of distortion products was also examined. Many in the professional audio community remember a Neve designed equalizer which had a front panel control labelled "warmth". Neve explained that this knob controlled the level of second harmonic distortion introduced into the signal, and how in the final version of the product, as much as eight percent harmonic distortion could be dialed in. Mr. Neve explained that as the control produced exactly the effect its named would suggest, he regarded this as vindication of his opinions on the subject of distortion.
This is not to suggest that Neve designs produce high levels of distortion, only that even order distortions are more acceptable and in some circumstances desirable. To illustrate that accepting harmonic distortion, provided it is below the noise floor of the equipment in question, can be misleading, a simple experiment was conducted: a three kilohertz tone was mixed with pink noise and played over the monitor system. The tone was gradually dropped in level until a majority of the audience agreed that the tone was in effect inaudible: at this point the tone was thirty decibels below the level of the noise. The goal of the exercise was to illustrate the ability of the human auditory system to extract information from a complex signal, in effect, to hear distortion below the noise floor of the system. Mr. Neve explained that in view of this ability it was important to design for very low levels of distortion and in particular to pay attention to designing for more musically acceptable distortion products ie: even order.
A similar listening test was conducted to clarify the reasons for the desirability of wide bandwidth design. By switching between a high frequency sine wave and a square wave of the same frequency and amplitude it was suggested that it is possible to distinguish the sine from the square even though the nearest harmonic of the square wave is beyond the normal range of hearing, the implication being that the ability of the circuit to cope with spectral content beyond it normal operating range while handling a signal within the audible range can have large implications on the perceived sonic qualities of the device under real world conditions.
Mr. Neve's talk was peppered with anecdotes and amusing references and one in particular stands out: the story of a very young Rupert Neve setting up a microphone and public address system for a political convention at which the redoubtable Winston Churchill was to speak. A torrential downpour forced the venue to a large tent where a dripping Rupert Neve quickly patched together a workable system just as Churchill approached the podium. Mr Churchill quietly asked Neve for direction in using the system and as Mr. Neve remarked, "I had the opportunity, if only for one minute, to tell Winston Churchill what to do!". Think about it...
Mr. Neve's visit was sponsored by Sonotechnique, and we thank Paul Fleury and Gerry Eschwheiler for their help in making this meeting possible.
And of course, thank you, Mr Neve.
In Toronto, Denis Tremblay
John Vanderkooy offered his annual Everyman's Guide to the AES Papers, stopping to highlight a few, and focussing on one in particular which he had presented himself on behalf of Eric Benjamin.
Our Chairman Tom Shevlin presented a slide show on his version of the Convention, as seen from the Exhibition floor, and Barry Lubotta presented a review of literature (via an opaque projector which threatened to vapourize any material left inside it for more than a few moments) he had collected from the same floor, and Martin Procunier added an impromptu summary of areas which had interested him.
All three had been at the same convention, but all three had entirely different perspectives to share, which left those of us unable to attend the actual event with a well-balanced and fascinating impression of what was presented at the show.
A Survey of the Opinions of Members of
the Toronto Section AES Audio Community
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Back to October 1993
Copyright 1993, Audio Engineering Society Toronto
Section BulletinArticles may be used with the Author's Permission. Contact the Bulletin Editor: earlm@hookup.net
Editor: Earl McCluskie Assistant Editor: Anne Reynolds Layout Editor: Lee White
The Bulletin is prepared in print by Lee White, and on Horizons and the Internet by Earl McCluskie.
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