From Gerry Harant
Blackburn Victoria Australia
In the late Thirties, when small “mantel” radios first became a possibility,
the tinny sound of a small speaker in a small cabinet caused engineers to look
for a way out. As it was well known that the ear “invents” a fundamental which
is absent from a harmonic-rich sound, the obvious answer was to accentuate or
invent a second-harmonic distortion component, which could easily be done with a
few passive components using valve nonlinearity.
I am thrilled to find that Philips engineers have now discovered that, by
using a special frequency-doubling chip, they can create a mathematically
identical effect (Technology, 14 June, p 20).
Other simple ideas were around at the time, such as a small pilot globe
connected across the loudspeaker voice-coil to produce a very passable volume
expander. All this and lots more is to be found in old textbooks.
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I expect that any day now someone will invent a round thing that rolls along
the ground and minimises friction, only it will need a 200-megahertz Pentium
processor to do it.
