Crown P.I.P.-BP1C, Справочное руководство, Страница: 6 / 26

Page 6
P.I.P.–BP1X & P.I.P.–BP1C
Reference Manual
response that must be corrected elec-
tronically by this filter. The actual re-
sponse is determined by the
combination of a stage of first-order
boost (controlled by switches 8, 9, and
10) and a stage of second-order high-
frequency roll off (controlled by
switches 1-6),
Note: switch 7 is not active and can be
set at either the“ON” or“OFF”position.
The loudspeaker manufacturer deter-
mines the frequencies to which these
switches should be set. Constant-Di-
rectivity Horn Equalizaion is factory-
set to Flat. Refer to Figure 2.7a for
–3-dB low pass roll-off frequency set-
tings and corresponding switch posi-
tions. Refer to Figure 2.7a for +3-dB
shelving frequency settings and cor-
responding switch positions. Figure
2.8 shows sample response curves.
G. Compressor Threshold
Potentiometer
The compressor occurs in the signal
path after the filters and equalizers. A
variable-threshold signal-driven com-
pressor is provided and by default is
ON and is error driven. With error-
driven compression, the compressor
will activate if the amplifier clips, re-
gardless of the output signal. Error-
driven compression is useful when the
possibility of over-driving the amplifier
by several dB is present and the re-
sulting distortion is unacceptable.
Reducing the output voltage at which
the compressor will activate is useful
for applications where driver and/or
system protection is desired. Com-
pression will then limit the output volt-
age to a predetermined level, even as
the input to the amplifier is increased.
Attack time is 10 msec and release
time is 360 msec. The compressor
has an infinite compression ratio,
meaning that when the threshold is
reached, an increase in input level will
not result in a change in output level.
The range of compression is 16 dB. If
the input is driven more than 16 dB
over the threshold, the portion of the
signal over 16 dB will be passed lin-
early. At that point, the next limit to
output will be amplifier clipping. (See
Figure 2.9 for a table of potentiometer
settings and the corresponding volt-
age and power outputs from the am-
plifier.)
H. Compressor Control
This two-position jumper block con-
trols the feedback path that will drive
the compressors. The compressor in
a certain channel can be controlled by
the error amplifier of that channel, the
error amplifier of the other channel, or
neither (compressor turned off). When
the compressor is turned off, no ampli-
fier condition, whether it is high output
voltage or clipping, will cause the com-
pressor to activate. To turn the com-
pressor off, place the jumper on only
one pin of the jumper block.
I. Daisy Output Jumpers
These two-position jumpers are used
to select between sending the pro-
cessed signal (NORM) and the un-
processed signal (BYPASS) to the
daisy chain outputs. Sending the pro-
cessed signal to the daisy chain out-
puts will allow two or more amplifiers to
run off of the same processed signal,
so only one
P.I.P.–BP1 would have to
be used (the signal needs only to be
processed once for all of the amplifiers
that need the signal). Sending the un-
processed signal to the daisy chain
outputs will enable the use of other
P.I.P.–BP1 modules with different DIP
switch settings or the use of other
P.I.P.
modules to perform different functions
on the same input signal. Both jumpers
of each channel must be in the same
position for correct operation.