(4.0E)
5-3
5.2.
Wiring
We recommend the use of good quality cables with a minimum
1.5 mm
2
conductor size - 2.5 mm
2
is preferable.
d&b can supply MC8 CA-COM terminated cables (8 x 2.5 mm
2
) in
various lengths. Especially for long cable runs, we recommend
using d&b MC1220 cable. The coaxial construction of MC1220 mi-
nimises crosstalk and external signal interference.
d&b SenseDrive can compensate for cable losses provided the sum
of the required voltage at the loudspeaker terminals and the volta-
ge loss in the cable does not exceed the maximum available volta-
ge the power amplifier can deliver. Therefore, the length of cable
run between mainframe and loudspeaker should be kept as short
as possible, particulary when the full output capability of the sy-
stem is needed.
If in an installation very long cable runs are unavoidable, a con-
ductor size greater than 2.5 mm
2
may be needed to reduce power
loss and to achieve an acceptable damping factor - the ratio of the
load impedance to the cable impedance being a critical factor. If
the size of the individual conductors in a cable is insufficient, then it
may help to double-up the conductors to achieve an acceptable
thickness of copper.
The following rule of thumb formula allows you to estimate the
maximum cable length with an acceptable damping factor (>10):
maximum (single) length of cable =
3 x load impedance [
Ω
] x cross-section [mm
]
