Specifications

Digidesign Plug-Ins Guide76
About Peak Limiting
Peak limiting is an important element of audio
production. It is the process of preventing signal
peaks in audio material from clipping by limit-
ing their dynamic range to an absolute, user-se-
lectable ceiling and not allowing them to exceed
this ceiling.
Limiters allow you to select a threshold in deci-
bels. If an audio signal peak exceeds this thresh-
old, gain reduction is applied, and the audio is
attenuated by a user-selectable amount.
Limiting has two main uses in the audio produc-
tion cycle:
• Adjusting the dynamic range of an entire final
mixdown for premastering purposes
• Adjusting the dynamic range of individual in-
struments for creative purposes
Limiting a Mixdown
The purpose of applying limiting during final
mixdown is to flatten any large peaks remaining
in the audio material to have a higher average
signal level in the final mix. By flattening peaks
that would otherwise clip, it is possible to in-
crease the overall level of the rest of the mix.
This results in higher average audio levels, po-
tentially better signal to noise ratio, and a
smoother mix.
Limiting Individual Instruments
The primary purpose of applying limiting to in-
dividual instruments is to alter their dynamic
range in subtle or not-so-subtle ways. A com-
mon application of this type of limiting is to
modify the character of drums. Many engineers
do this by applying heavy limiting to flatten the
snap of the attack portion of a drum hit. By ad-
justing the release time of the limiter it is possi-
ble to bring up room tone contained in the de-
cay portion of the drum sound.
In some cases, this type of limiting can actually
change a drum’s character from a very dry
sound to a relatively wet sound if there is
enough room tone present. This method is not
without its drawbacks, however, since it can also
bring noise levels up in the source audio if
present.