Nexo GEO S8 - Manual (Page 8)

P.8 GENERAL SET-UP INSTRUCTIONS
G ENERAL S ET - UP I NSTRUCTIONS
Speaker Wiring
The loudspeakers are connected to power amplifiers via
NL4FC SPEAKON connectors (not supplied). A wiring
diagram is printed on the connection panel located on the
back of each cabinet. The in/out pins of the SPEAKON
sockets are identified. The sockets are connected in
parallel within the enclosures (see the Connections
Diagrams section of this manual). Either connector can
be used to connect power amplifiers or to power an
additional GEO Tangent Array Module (NEXO
recommend a maximum of six S Series Tangent Array
Modules per amplifier channel).
NB: The front loudspeaker of the CD12 is wired 2+ & 2-
while the rear loudspeaker is wired 1- & 1+. NEVER
connect the CD12 to the GEO S805/S830.
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 Ohms, L
max
in meters
The table below indicates these values, for 3 common sizes.
Load Impedance ( Ω) 2 3 4 6 8 12 16
Cable section Maximum Length (meters)
1,5 mm² (AWG #14) 3 4.5 6 9 12 18 24
2,5 mm² (AWG #12) 5 7.5 10 15 20 30 40
4 mm² (AWG #10) 8 12 16 24 32 48 64
Examples :
The GEO S805 and S830 have a nominal impedance of 16 ohms, so a 6x GEO S8 cluster wired in parallel
will present a 16/6 = 2.7 Ohms load impedance. The maximum acceptable 2x2.5 mm
2 (AWG #12) cable
length L
max
for such a cluster is 6.75 meters.
The CD12 subwoofer has a nominal impedance of 2 x 6 Ohms, therefore 2 CD12s wired in parallel will
present a 2 x 3 Ohms load impedance. The maximum acceptable 4x4 mm
2
(AWG #10) cable length L
max
is
then 12 meters.
IMPORTANT NOTE: Long speaker cables induce capacitive effects – up to hundreds of pF depending on the
quality of the cable, with a low-pass effect in high frequencies. If long speaker cables must be used, ensure
that they do not remain coiled while in use.