5
CHAPTER 2
Self-powered and highly mobile, the 700-HP subwoofer is
advanced loudspeaker technology with equally advanced
power capabilities. Understanding the 700-HP subwoof-
er’s power distribution, voltage and current requirements,
as well as electrical safety issues, is critical to the safe
and correct operation and deployment of the 700-HP
subwoofer.
AC POWER
When AC power is applied to the 700-HP subwoofer, the
Intelligent AC power supply automatically selects the cor-
rect operating voltage, allowing the 700-HP subwoofer to
be used internationally without manually setting voltage
switches. The Intelligent AC power supply performs the
following protective functions to compensate for hostile
conditions on the AC mains:
■
Suppresses high-voltage transients up to several kilo-
volts
■
Filters common mode and differential mode radio
frequencies (EMI)
■
Sustains operation temporarily during low-voltage
periods
■
Provides soft-start power-up, eliminating high inrush
current
VOLTAGE REQUIREMENTS
The 700-HP subwoofer operates safely and without audio
discontinuity if the AC voltage stays within either of two
operating windows at 50 or 60 Hz:
■
85 to 134 volts
■
165 to 264 volts
The 700-HP subwoofer can withstand continuous voltages
up to 275 volts and allows any combination of voltage to
GND (that is neutral-line-ground or line-line-ground).
CAUTION:
Continuous voltages higher than
275 volts can damage the unit.
TIP:
Since the 700-HP subwoofer does
not require a dedicated Neutral, and it can
tolerate elevated voltages from ground, it can be
connected between Line-Line terminals in a 120
V 3-phase Wye system. This results in 208 V AC
betweens lines (nominal) and will therefore draw
less current for the same output power compared
to operating the 700-HP subwoofer from 120 V AC
(Line- Neutral). Make sure that the voltage remains
within the 700-HP subwoofer’s recommend oper-
ating window (180 V AC to 250 V AC). The Ground
terminal must always be used for safety and the
Line to Ground voltage should never exceed 250
V AC (typically there will be 120 V AC from Line to
Ground in the above example).
The 700-HP subwoofer uses a NEMA L6-20P, an IEC 309
male power connector or a multipin VEAM connector and
complies with worldwide product safety standards.
AC POWER DISTRIBUTION
All amplifier modules and directly associated audio equip-
ment (mixing consoles, processors, etc.) must be properly
connected to the AC power distribution, preserving AC
line polarity and connecting earth ground such that all
grounding points are connected to a single node or com-
mon point using the same cable gauge as the neutral and
line(s) cable(s).
Improper grounding connections between loudspeakers
and the rest of the audio system may produce noise, hum
and/or serious damage to the input/output stages in the
system’s electronic equipment.
CAUTION:
Before applying AC to any
Meyer Sound self-powered loudspeaker, be
sure that the voltage potential difference between
neutral and earth ground is less than 5 V AC.
Figure 2.1 shows a sample three-phase AC distribution
system, with the load between loudspeakers distributed
among the three phases and all of the loudspeakers con-
nected to common neutral and earth ground points.
Line 1
Line 2
Line 3
Neutral
Earth Ground
Figure 2.1. A sample AC power distribution block diagram.
CHAPTER 2: POWER REQUIREMENTS
