8
CABLE REQUIREMENTS
Input Cables
Make sure to use only shielded cables whether balanced or unbalanced. As a rule,
unbalanced lines of over 3 meters long are not acceptable. Shielding, when properly
grounded, protects a signal against external radio interference, interference generated by
dimmers and other electric noise. Avoid placing input cables close to power cords or power
transformers.
Output Cables
The amplifier is capable of delivering high level output current; therefore, the wire
gauge used for speaker cables is particularly important. Inadequate wire gauge adds
significant resistance to the speaker’s own impedance, reducing the power which is
actually delivered to the speaker. It will also result in a decreased damping factor and
possible fire hazard.
Since the power applied to the loudspeaker is of primary concern in system design,
we have included the table below to allow you determine the appropriate wire gauge for
your application.
The table shows the percentage of the power loss in a 10-meter 2-conductor copper
cable. This table reflects the power loss as a percentage of the output power of the ampli-
fier, applied to the load.
Use this table to determine the power loss to the load for other cable lengths. For
example, if you plan to deliver 100 Watts to 8-Ohm load through 20-m cable of 0.75 mm
2
gauge, the power loss in the cable would be 5.8 % x 2=11.6 % of 100 W or 11.8 W lost in the
cable.
Power Loss in a 10-meter Cable
Wire Gauge, mm
2
Cable
Resistance,
Ohm
Cable Power Loss
4 Ohm Load
8 Ohm Load
0.50
0.75
1.00
1.50
2.00
2.50
4.00
0.72
0.49
0.36
0.24
0.18
0.15
0.09
15.4 %
10.9 %
8.3 %
5.7 %
4.3 %
3.6 %
2.3 %
8.3 %
5.8 %
4.3 %
2.9 %
2.2 %
1.8 %
1.1 %
