Solidyne AUDIMAX 362, Руководство пользователя

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AUDIMAX 362
SOLIDYNE
MPX processing
The studies about the modulation on an FM
transmitter indicate that when the transmitter is
modulated by stereo MPX signal appears a new
effect, not present on the original audio signal.
This effect, denominated in U.S.A. MPX
Interleaving (also known as peak correlation ),
determines that the modulation peak in MPX does
not coincide with the modulation peak of the
stereo signal, considered in independent form.
This means, in simple terms, that if the peaks of
channels L and R are limited separately so that
MPX signal never over modulate, during most of
the time, the modulation capacity of the
transmitter will be wasted. And this happens
because signal MPX is the sum of L+R but also
includes the 38 KHz sub-carrier. According to the
relation of phase between these three elements,
there will be different peak values for the
interleaving. This phenomenon indicates that is
possible to increase the modulation without
increasing the deviation of 75 KHz of the
transmission, taking advantage of the modulation
capacity that normally is wasted.
Audimax 362 processor uses a MPX Processing
technology named Super Modulation. This
processing consists on a system that controls the
peaks, operating at 608 Khz, eliminating the
peaks in MPX base band signal and filtering them
so that there are not left residual components.
REFERENCES
1.-
S. S. Stevens, The measurement of loudness, ASA
Journal, Vol.27, pg. 815.
2.-
S. S. Stevens, The direct estimations of sensory
magnitudes-loudness; American J. Psychol. 69, 1-25,
1956.
3.-
S. S. Stevens, Concerning the form of the loudness
function; ASA Journal, Vol. 29, pg 603-606, 1957.
4.-
E. Zwicker – Flottrop – Stevens; critical bandwidth
in loudness sumation, ASA Journal, Vol. 29, pg. 548-
557, 1957.
5.-
Stanley Gelfand, Hearing, pg. 392, Edited by M.
Dekker, N. York, 1990.
6.-
Oscar Bonello
.
NEW IMPROVEMENTS IN AUDIO
SIGNAL PROCESSING Journal of the Audio
Engineering Society, Vol. 24 Nº 5. USA, 1976
7.-
Oscar Bonello PC CONTROLLED
PSYCHOACOUSTIC AUDIO PROCESSOR, 94th
Audio Convention, Berlin March 1993
8.-
Oscar Bonello, Burst Masking (Enmascaramiento
por Ráfaga) Anales del II Congreso Iberoamericano de
Acústica, Madrid, octubre 2000
9.-
Oscar Bonello, Multiband Audio Processing and Its
Influence on the Coverage Area of FM Stereo
Transmission, Journal of Audio Engineering Society,
New York, March 2007