Panasonic AV-HLC100E Operating Instructions Manual page 78

FIGURE 81
Compressor Limiter
The Compressor/Limiter is capable of preventing clipping (see Section 13.9.1) from unexpected peaks
or transients, and making talent sound better than they do in real life, bringing voices, music and other
audio sources into an optimal dynamic range. Being able to do this independently for each output too is
icing on the cake, especially for Internet streaming, as it ensures correct levels at any time.
T
HRESHOLD
Sound above the set Threshold level will be compressed; the amount of compression and the manner in
which it is applied are both dictated by the other settings.
R
ATIO
A Ratio of 4:1 means that if input level is 4 dB over the threshold, the output signal level after compression
will be just 1 dB over the threshold. The gain (level) is reduced by 3 dB. Very high ratio settings are the
reason the word "limiter" is part of the title for this feature. The highest ratio setting will effectively reduce
any signal that would rise above the threshold all the way down to the threshold level (with the exception
of a brief period during a sudden increase in source loudness, as dictated by the Attack setting).
Compressor ... Limiter – what's
the difference, anyway?
Compression and limiting are
not really different processes,
but rather a matter of degree
and perceived effect.
Compression, ideally, takes
the form of a subtle, almost
imperceptible modulation of
the sound level to bring it into
a more pleasing and
convenient range. A limiter is
applied more for the purpose
of managing, even 'crushing',
unwanted spikes and
transients.
That distinction aside, a limiter
is essentially just a
compressor set to a high ratio
and, generally, a fast attack
time. Audio engineers typically
consider 'compression' with a
ratio of 10:1 or more as
'limiting'.
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