Attack timing, 5 attack timing – Sonnox Oxford Limiter User Manual
Page 9
5 ATTACK TIMING
5 Attack Timing
The addition of
an
ATTACK timing control is a significant departure
from conventional limiter applications, and
requires some explanation for the best results.
Because
the level detection within the plug-in looks ahead of
the gain control, peaks in the programme material
are acted upon in advance of the gain reduction
process. Therefore, at the fastest setting of
the attack control, programme peaks are controlled
within a very small margin (less than +0.25dB, with
respect to continuous sine input conditions).
The
ATTACK fader allows the attack time to be increased to achieve a favourable
improvement in the sonic qualities of the peak reduction process, by allowing peak
programme transient events to escape hard gain reduction. Since the plug-in has internal
headroom, these overshoot peaks are retained and
are not clipped.
Peak overshoots resulting from a combination of the programme material and the action
of the Pre-Process stage are then passed to the enhancement section where their sonic
signatures can be added to the final programme sound. Providing
SAFE MODE is
selected, or the
ENHANCE fader is set to 100% or more in Normal Mode, no output
sample value overloads will occur from the plug-in, regardless of
ATTACK or RELEASE
time settings.
A combination of slower attack times and the enhancement process is therefore a very
powerful way to include transients in the output programme that would normally be
removed by conventional limiting processes. It can create a sonic quality and impression
of dynamic range that belies the degree to which the programme is actually being
limited.
As an example of the difference this can make, if slower attack settings are used without
the enhancer, and the output gain is reduced to accommodate the overshoots (avoiding
overloads), using the same attack settings with the enhancer can create up to (and
beyond) a 3dB increase in average level, being able to legally increase the output gain
setting and around another 2dB of perceived loudness due to the enhance action itself.
This can result in a perceived loudness increase of 5dB to 6dB!