Fender SPL-M500 User Manual
Page 6
Power and audio signal cables are the most
common sources of sound system failure. Well
made and carefully maintained cables are essential
to the reliability of the entire system. If long speaker
cables are required, make sure the wire is of
sufficient size to transfer all of the available amplifier
power to the speakers rather than absorbing power
itself. As a rule of thumb, the larger the wire the
better (larger wire has smaller "gauge numbers").
Below are two charts listing speaker wire gauges
and recommendations for best results.
Larger diameter (small gauge number) wire is
expensive and long cables made from it are heavy.
Rather than running long speaker cables, it is better
to locate power amplifiers near speakers and run a
line-level signal cable over the long distance to the
amplifier. This approach eliminates most of the
signal loss due to speaker cable resistance so the
speakers are fed all of the amplifier's power without
the need for heavy cables. In cases where speakers
and power amplifiers are located far away from the
signal source, "balanced line" cables are a wise
choice. Doing so can actually save money.
The use of stranded wire is highly recommended
since it is flexible and less prone to metal fatigue
breakage. If an end is nicked while insulation is
being stripped for connection, only one or two
strands will break and not the entire wire.
NEVER use coiled cords for
speaker hookup, even in an
emergency.
Coiled guitar-type cords usually have higher internal
resistance than the speakers themselves. This is
due to the light-gauge wire used to keep the coil
cords flexible. Unfortunately, these types of cord
prevent most of the power from reaching the
speakers. In high power operation, a coil cord can
melt causing a fire hazard and possible damage to
the amplifier. As a general rule, both straight and
coiled guitar-type connecting cords make poor
speaker cables.
The SPL-M500 can produce enough power output
to damage electronic equipment connected to its
output. Besides being capable of destroying
speakers, shock and / or fire hazards are also
possible. High power amplifiers should always be
properly applied and used with care in a clean and
dry environment.
Be sure to turn on all other equipment before turning
on the SPL-M500 power amplifier. This will prevent
turn-on "thumps" from the mixer or other pieces of
gear that could possibly damage speakers.
Likewise, the reverse logic should also be applied --
turn OFF the amplifier FIRST -- when shutting down
the system.
6
BASIC CONNECTIONS and WIRING
*Example - If the speaker wire length
required is between 25-50 feet (7.60-15.25
meters) and the speaker impedance is 8
Ω
,
the minimum recommended speaker wire
gauge is 16.
10
12
14
12
14
16
14 *16
18
16
18
18
18
18
18
8
10
12
14
16
4
Ω
*8
Ω
16
Ω
2
Ω
100'-UP
(30.5 m-UP)
50'-100'
(15.25-30.5 m)
*25'-50'
(7.60-15.25 m)
10'-25'
(3.05-7.60 m)
0'-10'
(0.00-3.05 m)
SPEAKER WIRE GAUGE
SPEAKER IMPEDANCE [z]
SPEAKER WIRE
LENGTH
AWG
Resistance in
Ω
per foot
(30.5 cm) @ 77º F (25º C)
18
16
14
12
10
.00651
.00409
.00258
.00162
.00102
8
.00064
0.83
1.32
2.10
3.32
5.27
8.38
mm
2