Nexo RS - Manual (Page 18)

Page 18/54 RS18 G ENERAL I NSTRUCTIONS
1.2.3 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)
2,5 mm² (AWG #12) 5 10 20
4 mm² (AWG #10) 8 16 32
1.2.4 Example
• Each RS18 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 RS18 with its 2 drivers in parallel is
10 meters.
• When driven in directional mode, RS18 requires 2 amplifier channels, presenting therefore two
independent 8 Ohm load impedances. The maximum acceptable 4x1.5 mm 2 (AWG #110) cable
length L
max
for RS18 with its 2 drivers driven independently is 32 meters.
IMPORTANT
Long speaker cables induce capacitive effects – up to hundreds of pF depending on the
quality of the cable - with a low-pass-pass effect on high frequencies. If long speaker
cables must be used, ensure that they do not remain coiled while in use.
OMNI
MODE
DIRECTIONAL
MODE