Pix of the meeting. Four pix on two 39K GIFs.
AES PNW Section Meeting Report
AudioControl Industrial IASYS - November 21, 1996
On November 21, 1996, two dozen members and guests of the Section heard a
presentation by Tom Walker, of AudioControl Industrial, describing the new
Iasys electro-acoustic analyzer.
The original idea for the analyzer came from Robert Reams; insights into the
design of the device were gained when he read and re-read the papers of the
late Dr. Richard Heyser. He then developed the analog and digital hardware
with Dwight Freeman, Robert developing the analog portion and Dwight the
Dwight also developed the software. Dennis Griffiths worked with Dwight to
insure the hardware and software worked well together on all of Iasys'
The Iasys has 4 major distinctions compared to other audio analyzers,
according to Walker:
It is designed to give answers, not interpretable data;
It gives the user a better sounding sound system fast;
It is something you can use every day; and
It allows you to precisely calibrate tools you already have.
He said existing analyzers are created for engineers and PhD's to use, not the
average mixers at live events or sound contractors installing permanent
The device performs four tests:
It will recommend the appropriate crossover frequency
for each component in multi-way systems, and then displays the relative level
of each bandpass, all operating one at a time in the acoustic environment in
which the system will be operating, making the bandpass levels simple and easy
2) Delay and Polarity
It will measure and display the distance from a tested component to the
microphone, as well as the relative distances between 2-4 components. It also
will test the acoustic polarity of the components, and can do so from a
distance as great as several hundred yards (assuming minimal interference from
wind), which allows you to check "mystery systems" without having to climb to
where the speakers are located.
3 Coherence and Equalizable Frequency Response
(Quoting from the brochure) "In real time this test measures the arrival
times of each individual frequency [1/12th octave steps] and displays in a +/-
percentage how close it is to the acoustic distance gathered in Test Two. With
the simple push of one more button Iasys will display a frequency response
curve showing only the frequencies that can be equalized."
This test highlights problems in component and array placement or arrangement,
room reflections, crossover/delay/equalization problems, and provides a means
of verifying probable intelligibility of the system. There is not a
correlation at this time to other intelligibility verification systems such as
4) Limiter Setting
It will tell you where to set limiter thresholds, and does so by examining
each component for the onset of thermal limiting. The system or bandpass
limiter would then be set to limit just before that onset.
Demonstrations of each of the tests were given at the meeting using two small
speaker systems, and IASYS seemed to do what it was designed to do.
It was an interesting and thought-provoking meeting.
Reported by Dan Mortensen, AES PNW Chair