TC Electronic Broadcast 6000 - Manual (Page 152)

Brickwall 2
148 System 6000 MKII Algorithms
subsequently low bit-rate data reduced. In such
cases try around -2 dBFS, and listen through the
encoder and decoder
Softclip
Range: Off, +18 dB, +12 dB,
+6 dB, 0 dB, -6 dB, -12 dB
When the post Gain level exceeds the thresh-
old set, Soft Clip is activated. When Soft Clip is
in operation, the red indications above the Gain
Reduction meters light up.
Soft Clip deliberately adds harmonic distortion,
and may be balanced against the adaptive lim-
iter for more apparent loudness, or as an effect.
However, when processing sensitive material,
and for live applications, it is recommended to
turn off Soft Clip to avoid bad surprises.
Upsample
When activated (green) Brickwall 2 operates at 5
times upsampling (regardless of System sample
rate) to detect and remove intersample peaks
above the Threshold. The I/O meters are con-
stantly upsampling to give an indication of po-
tential downstream distortion problems at the
input as well as the output. See the Threshold
description for more information.
Adaptive
Many different objectives exist when it comes
to peak limiting audio. From taking care of a few
peaks in a gentle way to pushing up the average/
peak ratio in order to raise the apparent loud-
ness, for voice cut-through or a dozen other rea-
sons. Brickwall 2 extends the adaptive release
time control of Brickwall 1 to include numerous
new internal variables, to make the algorithm re-
spond intelligently for a number of applications.
Activate Adaptive (green) to take advantage of
the different Profiles.
Profile
Range: Dynamic, Soft, Universal, Loud, Voice.
The adaptive Profiles allow you to tell Brickwall
2 what your intentions are. The selected Profile
is only active when Adaptive is pushed (green).
Several internal variables are dynamically updat-
ed based on the Profile chosen, so distortion is
perceived (and measured) to be as low as pos-
sible for a given loudness, and reduction in av-
erage/peak ratio. Maximum perceived distortion
tolerated is different from Profile to Profile. The
multi-dimensional parameter-space is fully con-
tinuos to avoid situations where distortion could
occur, or where processing is suddenly altered
without a detectible cause. Acquaintance your-
self with the different Profiles to have them at
hand when called for by a specific application.
The Dynamic Profile offers gentle processing
with minimum static and dynamic distortion. It’s
a first choice for audiophile limiting, for instance
with classical music, choir etc.
The Soft Profile also prioritizes low static and dy-
namic distortion over loudness, and is typically
suitable for acoustic music with natural tran-
sients and ambience, as well as live applications.
The Universal Profile has a higher tolerance for
perceived distortion than Dynamic and Soft. It is
still magnitudes better than analog designs, but
may be on the aggressive side for sensitive mu-
sic. It is a good choice for starters, and in pro-
duction where you don’t know what to expect.
The Loud Profile again has a higher tolerance
for perceived distortion, and is therefore better
suited for production and mastering rather than
live applications.
The Voice Profile is targeted human voice, and
adapts well to asymmetrical signals. Used on
composite material, perceivable distortion is to
be expected with large ratios of limiting.
Release
Range: 20 ms to 7 sec.
Because dynamic release times are included
with the adaptive profiles, Release becomes in-
active when Adaptive is selected.