User manual

24
General applications
8.3 The effect of
compression &
limiting on sound
Consider an input signal which is applied to two units, one having its threshold
point set 10dB higher than the other. Since the compressor only affects signals
that exceed the threshold level, the signal with the lower threshold applied will
be more affected than the other. Referring to figures 8.4a & b, assuming that all
Fig 8.3b Lower
threshold level
Fig 8.3a High threshold
level
Comparing the input and output waveforms for the compressed mode, the
loudest portions of the signal have been effectively decreased in level, and if
the gain control is adjusted to compensate for this, the quieter portions will be
other controls on both channels are set identically with gains equalised, it is
immediately apparent that the signal processed with the higher ratio is said to
have been limited, whereas the signal with the lower ratio is said to have been
compressed.
Fig 8.4b Effect of
compression with lower
ratio
Fig 8.4a Effect of
compression with high
ratio