3
PRODUCT PREPARATION
AMPLIFIER SELECTION
When choosing an amplifier, the maximum number of
speakers and the output level of each speaker must be
known. The sum of the tap settings should never exceed
80% of the amplifier’s rated output. For example, if
there are 5 speakers and the taps are set at 20 watts,
the load would be 100 watts (5 x 20 watts = 100 watts).
To arrive at the needed power for this number of
speakers, simply divide the total load by 0.8. In this
case, 100 / 0.8 = 125 watts. Therefore, a standard 125
watt amp would safely drive this load. To calculate the
amount of usable power an amp offers, simply multiply
the rated output by 0.8, i.e., 125 watts x 0.8 = 100 watts.
WIRE GAUGE – 70V/100V SYSTEM
The most common wire used on commercial 70
volt systems is 18 gauge, 2 conductor, stranded, and
jacketed without a shield. For outdoor applications,
direct burial type wire is recommended. The wire
starts at the amplifier location and is paralleled at each
speaker location. Maximum recommended wire length
using 18 gauge is up to 700 feet with a 100 watt load.
If you double the load (sum of your tap settings), you
will reduce the footage by half, to 350 feet. Conversely,
if you halve the load, you may double the acceptable
wire length, i.e., a 50 watt load is safe over 1400 feet
of 18 gauge. Stepping up to 16 gauge wire extends
the allowable run length by approximately 35%. For
example, a 100 watt load can go 700 feet on 18 gauge;
the same load may be placed on 1100 feet of 16 gauge.
WIRE GAUGE – 8 OHM SYSTEM
When using the product in an 8 Ohm system, the
total wire resistance should be less than 10% of the
speaker impedance. The speakers are nominally 6
Ohms impedance, so your total wire resistance should
be no more than 0.6 Ohms. In simple terms, the extra
resistance from the wire will have a very negative affect
on the sound quality of the speaker. The sound can
be less dynamic, definition of bass frequencies can be
reduced, and in extreme cases, the high frequencies
can be attenuated. Amplifier power is also wasted in
the wire, reducing the maximum output level of the
system. Please refer to the following chart (Figure 1)
when deciding on the appropriate wire gauge for
your installation.
WIRE RESISTANCE IN OHMS VS. LENGTH OF CABLE RUN
DISTANCE IN FEET
50’
100’
150’
200’
250’ 300’
20 GAUGE
.86
1.73
2.59
3.45
4.32
5.18
18 GAUGE
.65
1.30
1.94
2.59
3.24
3.89
16 GAUGE
.43
.85
1.28
1.71
2.14
2.56
14 GAUGE
.27
.54
.81
1.08
1.35
1.62
12 GAUGE
.17
.34
.51
.68
.85
1.02
INSTALLATION
In a typical 70V/100V mono configuration, multiple
OMNI-6T units can be wired in parallel along a single
2-conductor wire. Alternatively, a 4-conductor wire can
be used to alternate left and right channels for a stereo
configuration.
NOTE: Before placing speakers in their final locations,
ensure that each tap is set to the appropriate 70V/100V
or 8 Ohm setting (Figure 2). Never connect multiple
speakers set at 70V/100V and 8 Ohm to the same
circuit.
ADJUSTING THE TRANSFORMER
TAP SETTINGS
IMPORTANT: This product is IP66-rated for use in harsh
outdoor environments. Nevertheless, careful placement
of the speakers to reduce exposure to direct water
spray is recommended.
CAUTION: The amplifier should not be connected to AC
power until all speaker wire connections are completed.
70V/100V amplifiers present a serious shock hazard.
Figure 1: Wire Resistance
70V
OFF
20
40
80
NA
8Ω
OFF
20
40
80
8Ω
10
100V
SPEAKER PLACEMENT
The Omni-6T is designed to deliver a seamless, 360
degree omnidirectional sound field in an open air
environment. An array of multiple speakers should be
strategically placed to minimize ‘hot spots’ and ‘nulls’
as you move around the outdoor entertainment area.
Recommended placement of the Omni-6T speakers is
every 10-15 ft (3-4.5m) around the area of coverage.
The shorter spacing is recommended for higher SPL
and closer listening applications (Figure 3). For optimal
performance and visual integration into softscaping,
bury each speaker 6-8 inches (Figure 4). In hardscaping
applications, use the four 1/4” (6mm) mounting holes
in the base to secure the speaker onto its installation
surface (stainless steel mounting hardware not included).
Figure 2: Adjusting the Transformer Tap Settings
