User manual

(5.0E) 3-1
C6 controller front
view
C6
CUT
GRISP
MUTE
OVL
-12 dB
-6
+6
0
MON
160Hz
3. Controller modules
The controller modules include all the signal processing electronics,
front panel controls and indicators needed to control and operate
a specific matching loudspeaker system.
The P1200A mainframe can be fitted with two controller modules
with each module normally driving one of the two mainframe
power amplifiers. The two mainframe power amplifiers can also be
driven by a single controller module e.g. for a four cabinet mono
subwoofer system. However a special mono module needs to be
inserted in the unused controller module slot.
The controller module modifies the frequency response and the
maximum output level of the mainframe to suit the characteristics
of its matching loudspeaker. A loudspeaker driven with a non-
matching controller module will produce a corrupted sound and
there will be a risk of damage to the loudspeaker components.
3.1. Features
Input circuit
A balanced and band-limited input circuit protects the system
against out-of-band signals and radio frequency interference.
Equalisation
Equalisers match the relative levels of the high and low drivers
used in full range cabinets and ensure the linear frequency
response of the loudspeaker system. Some controller modules are
fitted with additional configuration switches to give the user a
degree of control over the system frequency response.
Highpass filter
A highpass filter circuit fine tunes the bass-reflex loudspeaker
enclosures used in these systems and also helps to maintain a linear
low frequency response while protecting the loudspeakers from
extreme sub bass signals.
Crossover filters
The controller modules for the subwoofer systems incorporate a
lowpass filter as an active crossover to a full range/TOP system.
Conversely, the full range systems have a switchable highpass filter
for use with an additional subwoofer system.
Thermal limiter
An internal control circuit simulates the loudspeakers voice coil
temperatures under the actual load conditions. The output of this
circuit is used to protect drivers by reducing the signal level when
critical temperature values are reached.
LF displacement limiter
A second internal control circuit simulates the mechanical
displacement of the LF driver cone and reduces the signal level
before over-excursion damage can occur.