Expander - Datavideo AD-300 Instruction Manual

The available compression ratios on AD-300 are listed as follows:

1:1 applies no compression. The input and output levels remain the same,
regardless of the threshold level.

1.6:1 applies subtle compression. This ratio is gentle and transparent
sounding. It will preserve the natural peaks and valleys.

2:1 applies light compression. This ratio smoothly controls the dynamics
without causing noticeable changes to tone and punch.

4:1 applies moderate compression. This ratio setting is slightly more
aggressive. It applies gentle transient control while retaining natural
dynamics.

8:1 applies medium compression. This ratio has tighter control over
transients. There will be subtle changes to tone, punch and loudness.

16:1 applies heavy compression. This ratio is aggressive. It will dramatically
reduce dynamic range, causing a signal to lose punch, clarity and presence if
pushed hard.

32/64/100:1 are limiting. At 100:1, the compressor essentially blocks the
signal from crossing the threshold.
Attack time (50 – 500 msec) is the time it takes for the compressor to complete the
gain reduction based on the compression ratio.
Decay time or release time (300 – 2000 msec) is the time it takes for the compressor
to bring up the output level to be the same as the input level once compression is not
needed anymore (input level is now below the threshold level).

Expander

An expander can be used to reduce background noise. It reduces the level of an audio
signal by applying gain reduction similar to a compressor but below the threshold
instead of above it.
The threshold control sets the level below which expanding will take place. The audio
signal will not be gain reduced if it stays above the threshold level. The audio signal
will be gain reduced by a ratio (see Ratio for more information) if it falls below the
threshold. AD-300 offers a threshold range of -66 to -48 dBu. Setting it to OFF disables
the expander.
22