Nexo RS - Manual (Page 17)

RS15 G ENERAL I NSTRUCTIONS Page 17/58
2.3.3 Cabling
NEXO recommends the exclusive use of multi-conductor cables to connect the system: the cable kit is
compatible with all the cabinets, and there is no possible confusion between Front and Rear drivers.
Cable choice consists mainly of selecting cables of the correct sectional dimension (size) in relation to
the load resistance and the cable length. Too small a cable section will increase both its serial
resistance and its capacitance; this reduces the electrical power delivered to the loudspeaker and can
also induce response (damping factor) variations.
For a serial resistance less or equal to 4% of the load impedance (damping factor = 25), the maximum
cable length is given by:
L
max
= Z x S S in mm 2 , Z in Ohm, L
max
in meters
The table below indicates these values, for 3 common sizes.
Load Impedance (Ω) 2 4 8
Cable section Maximum Length (meters)
1,5 mm² (AWG #14) 3 6 12
2,5 mm² (AWG #12) 5 10 20
4 mm² (AWG #10) 8 16 32
2.3.4 Example
• Each RS15 driver has a 8 Ohms nominal impedance; in omni mode, both loudspeakers can be
driven in parallel on one amplifier channel, presenting therefore a 8/2 = 4 Ohms load impedance.
The maximum acceptable 2x2.5 mm
2 (AWG #12) cable length L
max
for RS15 with its 2 drivers in
parallel is 10 meters.
• When driven in directional mode, RS15 requires 2 amplifier channels, presenting therefore two
independent 8 Ohm load impedances. The maximum acceptable 4x1.5 mm 2 (AWG #14) cable
length L
max
for RS15 with its 2 drivers driven independently is 12 meters.
IMPORTANT
Long speaker cables induce capacitive effects – up to hundreds of pF depending on the
quality of the cable - with a low-pass effect on high frequencies. If long speaker cables
must be used, ensure that they do not remain coiled while in use.
LEFT
(FRONT)
2-/2+
RIGHT
(REAR)
1-/1+
OMNI
MODE
DIRECTIONAL
MODE