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Omnia 6 Use and Installation Guide – Version 1.00a
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9. Multiple clipper stages (Clip) at the output.
Wideband AGC: A very flexible wideband leveler section provides smooth, transparent control of the input
program. This is achieved through two significant Omnia innovations, a dual referenced release gate and a
hidden, intelligent “makeup” gain algorithm. The dual gate reference is a unique process that correlates the
dynamics of the audio input signal to a “rolling” reference level, and from that information makes
conditional decisions affecting the character of the release function.
A user-adjustable Make-Up Gain feature incorporates a hidden control signal that determines when the
amplitude of the input program suddenly falls to a reduced level. It then adjusts the side chain gain in order
to “fill in” the softer program passages so that the average level is increased. This allows the AGC function
to operate with slower time constants, while significantly increasing the average audio level. These slower
overall time constants yield lower intermodulation distortion, contributing to Omnia's trademark sound.
Using Classical music for an example, the orchestra often plays forte, and then enters abruptly into a quiet
passage. Conventional AGC algorithms would hold the softer passage down until it was able to slowly
recover at the static release time setting, making such passages nearly inaudible at normal listening levels.
Omnia-6’s makeup gain function allows a hidden, faster time constant to provide quick recovery, but only
during the softer passage. As soon as the orchestra starts to play louder, the “makeup” time constant yields
control back to the primary AGC circuit, returning gain to the previous platform level. This sophistication
preserves the dynamic integrity of the signal while greatly enhancing the listenability of the program.
A built-in, multi-stage phase rotator ensures symmetrical clipping of positive and negative peaks, making
better use of the symmetrical limitations of the FM medium. (This feature may be defeated for a more
musically transparent sound at the expense of possibly increased distortion on certain voice material.)
Phase Linear, Time Aligned Crossovers: Most multiband audio processors make a compromise in the
crossover area in order to provide a flat dynamic frequency response. This is done to avoid audible peaks or
dips in the recombined frequency response as the individual band gains change during processing. In an
effort to minimize this problem, most processors use a fixed phase-offset in the crossovers. While such
treatment helps to minimize frequency response peaks and dips, it also results in a loss of phase linearity,
increasing "smearing', and reducing musical clarity.
In Omnia-6’s DSP implementation, the crossover networks are carefully time-aligned so that the
recombined spectrum remains flat, regardless of the amount of gain control being applied within any band.
This true phase linear response assures that harmonic overtones are not displaced in time. The result: the
truer, more natural, and more musical Omnia sound.
Additionally, Omnia-6fm features separate crossovers for the multiband AGC sections. The AGC crossover
section features user adjustable crossover frequencies (exclusive to Omnia), while the limiter section
contains its own six-way crossover with factory optimized non-adjustable crossover frequencies.
Five-Band AGC: Similar in character to the wideband AGC described above, but expanded to five bands,
this section has the ability to significantly add power and loudness to the audio while tailoring and pre-
processing it for delivery to the enhancement and multiband limiter sections. Each of the four crossover
frequencies has five user-adjustable settings.
Enhance: This section contains the Bass EQ and Stereo Enhancement controls. In the Omnia-6fm's unique
signal processing architecture, these controls are placed in their optimal position — between the multi-band