Audio and Acoustic DNA—Do You Know Your Audio and Acoustic Ancestors? 17width to less than twice the frequency range of the
audio signal, “Since FM could not be used to narrow the
transmitted band, it was not useful.”
Edwin Armstrong ignored narrowband FM and
moved his experiments to 41 MHz and used a 200 kHz
channel for wideband, noiseless reproduction. FM
broadcasting allowed the transmitter to operate at full
power all the time and used a limiter to strip off all
amplitude noise in the receiver. A detector was designed
to convert frequency variations into amplitude
variations.
Paul Klipsch was a personal friend of Edwin Arm-
strong: Mr. Klipsch had supplied Klipschorns for the
early FM demonstration just after WWII. This was
when Armstrong, through Sarnoff’s political manipula-
tion, had been forced to move FM from 44–50 MHz to
88–108 MHz, requiring a complete redesign of all
equipment. It was a stark lesson on how the courts, the
media, and really big money can destroy genuine
genius. Armstrong had literally created radio: the trans-
mitters, the receivers for AM-FM-microwave in their
most efficient forms. David Sarnoff made billions out of
Armstrong’s inventions, as well as an economic-politi-
cal empire via the AM radio networks. No court or any
politician should ever be allowed to make a technical
judgment. Those judgments should be left to the techni-
cal societies as the “least worst” choice.
The history of audio is not the forum for discussing
the violent political consequences—Sarnoff of RCA
totally controlled the powerful AM networks of the
time. In 1954 attorneys for RCA and AT&T led to Arm-
strong’s death by suicide. The current AM programming
quality put on FM leaves quality FM radio a rare luxury
in some limited areas.
The few, my-
self included,
who heard the
live broadcasts of
the Boston Sym-
phony Orchestra
over the FM
transmitter given
them by Arm-
strong and re-
ceived on the
unparalleled,
even today, prec-
edent FM receiv-
ers know what
remarkable transparency can be achieved between art
and technology.
Acoustic Measurements—Richard C. Heyser
(1931–1987)Plato said, “God
ever geometrizes.”
Richard Heyser, the
geometer, should
feel at ease with
God. To those
whose minds res-
pond to the visual,
Heyser’s measure-
ments shed a bright
light on difficult
mathematical con-
cepts. The Heyser
Spiral displays the
concepts of the
complex plane in a
single visual flash.
Heyser was a scien-
tist in the purest
sense of the word,
employed by NASA, and audio was his hobby. I am
quite sure that the great scientists of the past were wait-
ing at the door for him when he past through. His trans-
form has yet to be fully understood. As with Maxwell,
we may have to wait a hundred years.
When I first met Richard C. Heyser in the
mid-1960s, Richard worked for Jet Propulsion Labs as a
senior scientist. He invited me to go to his basement at
his home to see his personal laboratory. The first thing
he showed me on his Time Delay Spectrometry equip-
ment was the Nyquist plot of a crossover network he
was examining. I gave the display a quick look and said,
“That looks like a Nyquist plot!”
He replied, “It is.”
“But,” I said, “No one makes a Nyquist analyzer.”
“That’s right,” he replied.
At this point I entered the modern age of audio anal-
ysis. Watching Dick tune in the signal delay between his
microphone and the loudspeaker he was testing until the
correct bandpass filter Nyquist display appeared on the
screen was a revelation. Seeing the epicycles caused by
resonances in the loudspeaker and the passage of
non-minimum phase responses back through all quad-
rants opened a million questions.
Dick then showed me the Bode plots of both fre-
quency and phase for the same loudspeaker but I was to
remain a fan of seeing everything at once via the
Nyquist plot.