User Manual

Core Avid Audio Plug-Ins
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Compression reduces the dynamic range of signals that exceed a chosen threshold by a specific
amount.
Limiting prevents signal peaks from ever exceeding a chosen threshold, and is generally used to
prevent short-term peaks from reaching their full amplitude. Used judiciously, limiting produces
higher average levels, while avoiding overload (clipping or distortion), by limiting only some
short-term transients in the source audio. To prevent the ear from hearing the gain changes,
extremely short attack and release times are used.
n
Limiting is used to remove only occasional peaks because gain reduction on successive peaks
would be noticeable. If audio material contains many peaks, the threshold should be raised and
the gain manually reduced so that only occasional, extreme peaks are limited.
The following table lists the Compressor/Limiter III plug-in parameters:
Parameter Description
Levels panel
Phase invert button Inverts the phase (polarity) of the input signal, to help compensate for phase
anomalies that can occur either in multi-microphone environments or because of
mis-wired balanced connections.
Input/Output level meters Show peak signal levels before and after processing.
• Green indicates nominal levels
• Yellow indicates pre-clipping levels, starting at –6 dB below full scale
• Red Indicates full scale levels (clipping)
n
Unlike scales on analog compressors, metering scales on a digital device
reflect a 0 dB value that indicates full scale (fs)—the full-code signal level.
There is no headroom above 0 dB.
The clip indicators at the top of the Output meters indicate clipping at the input or
output stage of the plug-in. Click an indicator to clear it.
Threshold arrow The orange Threshold arrow next to the Input meter indicates the current threshold.
You can drag the arrow up or down to adjust the threshold. For more information on
threshold, see the Threshold row below in this table.
Gain Reduction meter
(GR)
Indicates the amount the input signal is attenuated (in dB) and shows different
colors during dynamics processing.
• Light orange indicates that gain reduction is within the “knee” and has not
reached the full ratio of compression
• Dark orange indicates that gain reduction is being applied at the full ratio (for
example, 2:1)