Operating Manual - nX, nXe, and nXp Power Amplifiers
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2.2 Input Signal Wiring
Use shielded wiring for balanced or unbalanced audio signals. Shielding which is properly grounded will protect the
signal from outside electrical interference such as RF, fluorescent lighting, and computer/display emissions. Unbalanced or
single-ended (tip-sleeve) lines of less than 10 feet are generally ok, but for greater distance or noisy field environments,
always
use balanced signal.
Each channel's Euroblock, 1/4" phone jack, and XLR inputs are wired in parallel, with XLR pin 2 (+) and pin 3 (-). When
using an unbalanced input, wire the hot signal to the input (+) euroblock pin, phone jack tip, or XLR pin 2, and also be sure to
wire the input (-) pin, phone jack ring, or XLR pin 3 to ground.
Do not leave the (-) input unconnected.
Avoid running low
level signal wires in close proximity or parallel to long speaker cables, AC power cables, or power transformers, as they can
induce hum or oscillation.
2.3 Output Speaker Wiring
nX amplifier outputs use Neutrik SpeakON
®
connectors because they are safe, secure, reliable, and fully enclosing all hazard-
ous voltage.
Wire guage:
nX amplifiers are capable of delivering high levels of output current, so the wire gauge used for speaker outputs is
important. Inadequate wire gauge, especially over long distance, adds significant resistance to the speaker’s own impedance, reducing
the power which is actually delivered to the speaker. It could also result in a decreased damping factor and potential fire hazard. Since
power at the speaker load is of primary concern in system design, refer to the table below to best determine appropriate wire gauge for
your application. The following table lists the resistance per 100 feet of common copper wire gauges, and also lists the
percentage
of
the speaker load power which would be lost as heat in an arbitrary 100 ft run of different gauges of 2-conductor copper speaker wire.
Wire gauge resistance/power loss for 100ft speaker cable
Wire Gauge Ohms/100ft
8 Ohm load
4 Ohm load
2 Ohm load
#8
.0605 Ohms
0.8%
1.5%
3%
#10
.1018 Ohms
1.3%
2.5%
5%
#12
.1619 Ohms
2.0%
4.0%
8%
#14
.2575 Ohms
3.2%
6.4%
12.8%
#16
.4094 Ohms
5.1%
10.2%
20.4%
#18
.6510 Ohms
8.1%
16.3%
32.6%
This table expresses the power loss as a
percentage
of the load’s power rather than the total amplifier output power in
order to accurately determine power loss at other cable lengths. For example, if you plan to deliver 150 watts to an 8 Ohm load
through
50
ft of 14 ga. cable, the power loss in the cable would be
half
that of a 100 ft run of #14 wire as shown in the table,
or 1.6% of 150W, which is an insignificant 2.4 watts. However, if you were to run
200 ft
of
18 ga
. cable to a 2 Ohm load, the
loss would be twice that of the 100 ft run shown in the table, or 65.2% of 250W, which is 163 watts lost as heat. Always be
sure to use adequate gauge speaker wire.
2.4 Remote Control Wiring
Remote DC level control (all models)
- Unshielded bell or telephone wire is sufficient for DC level control, as is
CAT5 cable. The V+ and GND pins from one amplifier channel
can
be shared with other remote DC level controls wired to
the same amplifier, however
do not connect this ground to any external grounds.
Remote Standby (nXe and nXp only)
- This is a logic level signal, use unshielded low gauge wire.
Fault (nXe and nXp only)
- This is also a logic level signal, unshielded low gauge wire is adequate.
Preset (nXe and nXp only)
- This is also a logic level signal, unshielded low gauge wire is adequate.
Data (nXe and nXp only)
- Four conductor telephone wire is suitable, as well as CAT5, but if shielded wiring is used
be sure to ground the source end of the shield.
Under no circumstances should shielding be left unconnected to ground, as the
added line capacitance will degrade the data signal.
Maximum data cable distance is 1,000 ft (305m).
