Omnia-6ex Use and Operation Manual – V: 1.20
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Interpreting the Gain Reduction Meter Displays
Through careful observation of the processing bargraphs, significant information can be acquired and analyzed
about the audio signal on a moment-by-moment basis. The yellow bar shows the average value of the gain
reduction, while the floating ball indicates the peak value of gain reduction.
Average
value
of
gain
reduction
Gain Reduction scale
Peak value of gain reduction
Gain
reduction
meter
(typical)
Since the processing algorithms in Omnia-6EX 'adapt' to the audio, it is capable of performing many different
processing functions at different times. The processing display bargraphs may appear to indicate different kinds of
operation with different program material. This behavior is primarily based on dynamic range differences in the
applied program material. For program material that is already processed or lacking dynamic range, the bargraphs
will indicate differently than with material that possesses a high degree of dynamic range. This is because audio
signals that lack dynamic range, naturally or by previous processing, will possess a lower peak to average ratio.
Conversely, audio signals with a wide dynamic range possess a higher peak to average ratio. The Omnia-6EX adapts
differently to each case.
For program material that has low dynamic range (or high RMS and low peak levels), there will be more activity in
the AGC sections and less activity in the Limiters. This behavior is due to the AGC sections response to high RMS
energy, while the Limiters are reacting to lower peak energy. Sometimes the Limiter section may not indicate any
action at all, especially on the top three bands. For Omnia-6EX, this is completely normal! Examples of this
behavior might be seen with heavily processed commercials or music, or with music passages of sustained level. A
good example is the Aerosmith CD “Pump.” This recording has very little dynamic range. Try any up-tempo
selection from this disk and you will see the Wideband-AGC section make initial adjustments along with small
amounts of limiting. Once adjusted, the Wideband-AGC section will stay deep in gain reduction, although with little
movement, and action within the limiters will be minimal.
When the programming has wide dynamic range (low RMS and high peak levels), the opposite will occur. The
Limiter section becomes active, while the AGC section will appear not to respond as much. During these events, the
Limiter sections could be working aggressively, while the AGC sections indicate little activity. Good examples of
programming able to cause this behavior: vocal passages, live voice, classical music, and passages with high
transient levels. Good test examples: almost anything classical, as well as almost anything by Steely Dan!
Also keep in mind that the AGC sections are designed to operate much more slowly than the Limiter sections,
primarily because of the nature of each function. Remember that the AGC sections operate on the program's RMS
energy. During gain calculations, the incoming program's “average” level is established, and gain adjustments, if
needed, are made based on those calculations. This is why the AGC sections will appear to move slower than the
limiters ... they are making changes, as needed, over relatively long time periods.
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