@crown®* System®Product Reference
AMB-5 Automatic Mixer (Page 4 of 5)
VCAgain control (Bus relays,DSPI,and
aux output controls) are only controlled
manually. No automaticmodefunctions
are available for VCAs routing signals
to output 2.
AUTOMATIC MIXING
Feature Set:
To make use of the automatic mixing
power of the AMB-5 the unit must be
configured with IQ software. Once the
unitisplacedinautomaticmodeandits
intelligence is fully configured, the unit
will mix without further outside commu-
nicationbeing necessary. Intelligenceis
programmable independently for each
VCA used to route signals to output 1.
Features making up the total mixing al-
gorithm are comprised of user defined
variablessetinsoftware.Thesefeatures,
also called algos, include:
• Max Gain
• Input Noise Gate
•Duck Priority
• Input Compressor
•Auto Level
• Output Compressor
• Gate Count
• Max Number of Open Mics
•Ambient Noise Control
Max Gain
The purpose of Max is to prevent feed-
back and provide a safety limit. Max
Gainis defined as themaximum gain of
the VCA regardless of interaction with
other algos any time an input is gated
on, or if the gate function is not used.
Max Gain may be set –100 to +25 dB
Gain for each VCA. Two global settings
are used to tie Max Gain to the manual
gain controls. These are Max Gain
Tracks Control Block andControl Block
Override. These are two switches which
are used, usually together, to allow for
smoothoperational control ofMaxGain
forsemi-automatic operation. The need
for this mode of operation may arise
when using third party control system
products or some types of IQ controls.
Input Noise Gate
Thepurpose of a noise gateistoattenu-
ate an input when little or no input sig-
nalis present. With the AMB-5 you con-
figure various parameters which define
the precise operation of the gating fea-
ture at each input. Several other auto-
matic features also depend on proper
operationofthegatingfunction.Param-
eters involved are:
• Gate is an ON/OFF switch to en-
ableor disable this feature for each
VCA.
•Threshold isa parameter that sets
the input level required to gate on
for each VCA. The range is –100 to
+25 dB sensed.
• Low Set is a parameter that sets
the gain of the VCA when the input
is gated off. The range is –100 to
+25 dB gain.
• Delay Time is the time delay in
seconds after the input level drops
below
Threshold
until the VCA ac-
tually gates off. The range is 0.2 to
30 seconds.
Duck Priority
Theduckpriorityfeatureallowsthemixer
to have a priority structure of up to six
levels. Parameters involved are:
•Duckpriority isan ON/OFF switch
tells each VCA whether or not they
participate in the priority structure.
• Priority level is a setting from 1 to
6 where 1 = highest and 6 = lowest
priority. Each VCA is set indepen-
dently.
Input Compressor
TheAMB-5mixer is equipped with both
input compressor and an output com-
pressor features. The inputcompressor
differs from a conventional compressor
due to its feed forward structure. This
feed forward technology prevents
“breathing” and virtually eliminates
“pumping.” The parameters for the in-
put compressor are:
•CompressoristheON/OFF switch
for each VCA.
•Thresholdisthesensedinput level
above which the compressor be-
gins to actuate. The range is –100
to +25 dB and is set at each VCA.
• Ratio may be set to 1:1, 2:1, 4:1,
8:1, 16:1, 32:1 or∞:1foreach VCA.
• Release Time is the time in sec-
onds to release compression at a
slope of seconds per 10 dB. The
range is 0.2 to 30 seconds for each
VCA.
• Attack Time is a global setting for
all VCAs and may be set to fast or
slowdependingonyourpreference.
Auto Level
The auto level feature of this unit is de-
signed to handle long term input level
variations to maintain a consistent out-
put level. This is basically done by se-
lecting a desired average output level
then setting up the other parameters to
define the response. Parameters in-
clude:
• Auto Level is an ON/OFF switch
that enables or disables the auto
level function for each VCA.
• DAOL (Desired Average Output
Level) is the target output level you
set. Once the auto level function is
working the VCA raises or lowers
gain as necessary to achieve the
DAOLgiventhe sensed input level.
The DAOL setting range is –100 to
+25 dB.
• Reaction Time is the time in sec-
onds to change gain 10 dB toward
the necessary gain structure to ob-
tain the DAOL. The range is 0.2 to
30 seconds.
•Idle Gain is the gain that the VCA
goesto whentheinputinitially gates
on. In other words it is the starting
point.Usedinconjunction withother
features this parameter can afford
the mixer a variety of complex ef-
fects such as ramping in of back-
ground music.
•AutoLevelGate Function is a glo-
bal setting that may be set to Open
To Idle Gain or Open To Last Posi-
tion. When set to Open To Idle Gain
an input will initially gate on to the
Idle Gain setting and the auto level
featurewilltake over fromthere.The
advantage to this setting is that it
allows for ramping and input gain
is the same every time a gate first
comeson.When setto OpenToLast
Position the auto level feature re-
membersthegain of the VCA at the
time the input last gated off so that
gaingoes back to that levelthenext
time that the gate opens again.
Output Compressor
The AMB output compressor is differ-
entthat a conventional output compres-
sor because you can actually choose
which inputs participate in output com-
pression. This can be a valuable tool if
you have microphones on some inputs
and a playback source on other inputs.
You might reasonably expect that the
playback source such as a CD or tape
player will not output level which would
require compression, so you might not
configure those inputs to participate in
the output compression scheme. Out-
put compressor parameters are prima-
rily per output rather than input and in-
clude:
• Compressor is a master ON/OFF
switchthatenablesordisables out-
put compression.
• Limiter is an ON/OFF switch for
each VCA that configures which in-
putsmayparticipateinoutputcom-
pression.
• Threshold is the sensed output
level above which the compressor
beginsto actuate. Therangeisfrom
–100 to +25 dB.
