User manual

C3 (1.0E)
C3 controller module
HFC
LFC
GR LO
ISP
GR HI
OV LO
OV HI
MUTE
C3
0
-6
-12
dB
+6
10
15
5
0
-5
20
100 1k 10k
20k
2
3
4
5
6
Typical change in frequency response
with increasing column length
(2, 3, 4, 5 and 6 deep)
C3 controller module switches
HFC switch and indicator
Selecting the HFC mode (High Frequency Compensation, yellow HFC
LED illuminated), compensates for loss of high frequency energy due
to absorption in air. The HFC switch should be used exclusively for
those cabinets covering the very far field. This guarantees the
correct sound balance between close and remote audience areas,
whilst the mainframes driving the array can be fed with the same
signal.
LFC switch and indicator
In LFC mode (Low Frequency Compensation, yellow LFC LED
illuminated), the low frequency response is extended down to
80 Hz for speech reinforcement without subwoofers.
Indicators
These indicators give a three stage indication of the C3 controller
signal levels.
– ISP (Input Signal Present, green) illuminates when the input
signal of the controller input exceeds a –36 dBu threshold value.
The ISP circuit is unaffected by the setting of the controller mute
switch and level control.
– GR (Gain Reduction, yellow) illuminates when the controller
limiter reduces gain by more than 3 dB.
– OV (Overload red) illuminates when the controller limiter
reduces gain by more than 12 dB or overload occurs in the
signal path (input signal too high) or when the amplifier gain is
reduced because the output current is too high (e.g. due to a
short circuit).
The limiter indicators show the condition of the HF and LF channels
independently.
Level Control
The detented level control adjusts the controller input sensitivity and
has a 18 dB range (–12 dB ... +6 dB) calibrated in 1 dB steps. The
controls are normally set to 0 dB.
Arraying C3 and C4 cabinets
Vertical array of C3 cabinets
A vertical array of C3 cabinets produces a precisely shaped
wavefront following the mechanical arrangement of the cabinets.
The cut off at the upper and lower limits of the vertical dispersion of
a C3 column is very sharp, and therefore precise aiming is
absolutely essential to address the desired audience area.
The vertical coverage angle of a single cabinet is 5° and this defines
the maximum splay angle between adjacent cabinets in a column.
This dispersion angle is achieved above approximately
5 kHz, while lower frequencies will disperse into a wider area
creating an overlap of the coverage patterns of the single cabinets.
Therefore directivity and the level of lower frequencies increases
with every cabinet added to the column. Two cabinets arrayed
vertically with a 5° splay angle produce a flat frequency response.
Longer columns will therefore boost low and low/mid frequencies
according to the graph on the right.