User manual

C3 (1.0E)
Digital equalizer
C4-TOP/SUB-CO
C3-CO
Array EQ
System EQ
C3-CO
C4-TOP/SUB-CO
0.3 ms
Delay
Input signal
C3 wiring with C4-TOP and C4-SUB
Digital equalizer
C4-TOP/SUB-CO
C3-CO
Array EQ
System EQ
C3-CO
C4-TOP/SUB-CO
B2-CO
C4-OUT
0.3 ms
Delay
Input signal
C3 wiring with C4-TOP, C4-SUB and
B2-SUB
Time alignment and signal distribution
When combining C3s and C4-TOPs the correct time alignment of
both systems is of great importance. To achieve this C3 and C4-
TOPs have to be driven by separate input signals. With a delay of
0.3 ms in the C4 signal path both systems are perfectly coherent
over the whole audio band, while the C3 signal path contains the
vertical array equalization as described above. To avoid the
influence of different latencies (inherent delays) of the signal chains,
make sure that the C3s and C4s in one array are driven with the
same signal processing devices using different outputs.
Normally C4-SUBs will be driven from the same signal processor
output as the C4-TOPs, or if B2-SUBs are used, from the C4-OUT of
the B2 controller. Should the B2-SUBs be driven separately (e.g.
when driven from an auxiliary output of the console or for time
alignment reasons), the low cut provided by the C4-OUT of the B2
controller can also be created for the C4 using a standard
parametric bandpass filter in a signal processor. The parameters are
f = 44 Hz, Q = 3, Gain = –6 dB.
Integration into the C4 flying system
The vertical splays between the cabinets of a C3/C4 array are set
by load chains of different lengths. d&b offer chains for 1°, 2.5° and
5° angles plus a shortening chain enabling greater variable angles.
For a coherent coupling of adjacent cabinets the precise alignment
of the rear panels of the cabinets is essential. Therefore it is
necessary to use the d&b Z5110.100 Hinge between the cabinets
throughout the whole column.
C3 arrays have a very high vertical directivity, therefore the use of
a precise digital angle finder to verify the desired aiming is strongly
recommended. Deviations of less than 1° can have an immense
impact on the coverage in the far field. A laser distance finder is
recommended to set the correct array height.
d&b TransCalc V3 is a Microsoft Excel based calculation tool for
planning the mechanical set up of the d&b Transformer flying
system. It computes all settings for the flying system plus dimensions,
weights, CAD export and a parts list for the whole rig. Version 3
now provides a graphic display for up to four listening planes in 2D
projections showing the aiming points of all C3 and C4-TOP cabinets
of the array. The above mentioned laser distance finder is a useful
tool to assess the dimensions of the listening areas.