Crown Audio IQ-P.I.P.-SMT - Manual (Page 13)

Page 13
IQ P.I.P.–SMT
3.8 Input Signal Compressor/
Limiter
An input signal compressor/limiter is
available for each channel. Each one
is controlled by the
IQ System and
has five parameters:
Input Compressor: Turns this
function on/off.
Threshold: Sets the threshold,
in dB, above which the
compressor acts. The level is
measured at the input to the
P.I.P. and corresponds to the
level shown on an input meter.
The compressor is “feed-
forward,” meaning that the level
detection point is located before
the gain control stage. The
range is from +16 dBu to –40
dBu.
Attack Time: Sets the attack
time of the compressor. The
attack time is the time it takes
the compressor to attenuate the
input signal by 10 dB. The range
is from 1 millisecond to 2
seconds.
Release Time: Sets the release
time of the compressor. The
release time is the time it takes
the compressor to increase the
input gain by 10 dB. The range
is 100 milliseconds to 30
seconds.
Ratio: Sets the compression
ratio for the compressor. The
range is 1, 2, 4, 8, 16, 32,
∞
to 1.
Note: 1:1 is the same as “off.”
3.9 Output Signal Level Monitor
The output signal level of each chan-
nel of the amplifier can be monitored
by the
IQ System. This monitor fea-
ture has a range from –40 dB to 0 dB
where 0 dB is referenced to the rated
output voltage of the amplifier model.
(This is assumed to be 70-V or the
rated 8 ohm output for
Com-Tech
amplifiers or the rated 8 ohm output
voltage for all other amplifiers.)
The output signal of some amplifiers
must be padded before the
IQ–P.I.P.–
SMT can scale them. This is accom-
plished by setting jumpers JP4 and
JP5 on the IQ circuit board to the “IN”
position. PIP2-compatable amplifiers
such as the MA 5000VZ and Com-
Tech "10" Series do not require these
pads. Set jumpers JP4 and JP5 to the
“OUT” position for them (see Figure
4.8).
The output signals of all amplifiers
must be scaled in order to “calibrate”
the 0 dB level. (See Section 4.5.) This
is accomplished with either an am-
am- am- am- am-
plifier ID code plifier ID code plifier ID code plifier ID code plifier ID code or a user scale fac- scale fac- scale fac- scale fac- scale fac-
tor tor tor tor tor. The factory default setting for this
is an amplifier ID code of “CT-70V”
which assumes that the output level
is that of a
Com-Tech amplifier (any
model) with both channels in the 70-
V output mode.
Note: PIP2-compat-
ible amplifiers are automatically
scaled by the IQ–P.I.P.–SMT.
3.10 Smooth/Output Signal
Limiter
An output signal limiter is available
for each channel. They can be used
either as “smooth” output levelers
(similar to older IQ
P.I.P.s with
SmartAmp features) or they can be
used as fast output limiters to protect
drivers and other system compo-
nents from large transient signals.
The output voltage of the amplifier is
limited (within 1 dB) based on real-
time sampling of the actual amplifier
output. The output limiters are con-
trolled by the
IQ System and have
five parameters: