Waves Linear-Phase MultiBand Software Audio Processor Speaker System User Manual


 
Waves LinMB software guide page 3 of 28
MultiBand devices are especially handy when dealing with the dynamics of a
full range mix. In a symphonic orchestra as well as in a Rock n Roll band
different instruments dominate different frequency ranges. Many times the low
range dominates the whole dynamic response while the higher frequencies
are riding on top. While it is the mixer’s or composer’s job to reach a desired
balance, mastering engineers often find they need to do something about the
dynamics of the mixed source. It may be to complement it further or indeed
improve its quality, or possibly just make it as loud as possible for competitive
level, with as little degradation as possible.
L
INEAR
P
HASE
X
OVERS
When the LinMB is active but is idle, it presents only a fixed amount of delay.
The output is 24bit clean and true to the source.
When we use Xovers to split a signal we like to think that they are splitting the
input signal to bands leaving everything else untouched. The truth is that any
normal analog or digital Xover introduces different amount of phase shift or
delay to different frequencies. Further dynamic gain changes will cause
further modulation of the Phase shift introduced by the Xovers. This
phenomenon was treated in C4’s phase compensated Xovers but the initial
phase shift caused by the Xovers is still apparent in C4 and in its output all
frequencies are equal to the source in Amplitude but not in Phase.
When its important to achieve as much source integrity as possible the LinMB
goes a long way and splits the signal to 5 bands maintaining a 24bit clean
starting point for applying different dynamics processing to each of the bands.
Transients are the main sonic events that benefit from Linear Phase.
Transients contain a wide range of frequencies, and are highly “Localized” in
time. A non-linear phase filter that shifts the phase differently for different
frequencies will “smear” the transient over a longer period of time. The Linear
Phase EQ will pass transients maintaining their full sharpness.
A
DAPTIVE
T
HRESHOLDS AND
D
E
-M
ASKING
When a soft sound and a loud sound happen at the same time, the loud
sound has some masking effect over the softer sound. The research of
Masking, articulated the Upward spread Masking, where loud low frequency
sounds mask higher frequency sounds. The Linear MultiBand provides a way
for each band to be sensitive to the energy in its “Masker” band. When the
energy in the Masker band is high the band’s threshold will rise to introduce
less attenuation and compensate for the masking, letting the sound in each
band come out as loud and as clear as possible. The Linear MultiBand is the
first processor to introduce this de-masking behavior, of which you can read
more in Chapter 3 of this guide.