Meyer Sound HMS-10TM - Manual (Page 10)

CHAPTER 2: HMS-10 LOUDSPEAKER
10
Calculating the Maximum Cable Length
The maximum cable length for an HMS-10 can be calcu-
lated with the following formula:
maximum length = 2 ohms / 2 * cable resistance
For example, the maximum length of an 18 AWG cable with
a resistance of 0.00636 is 157.2 feet (2 / 2 * 0.00636).
WIRING HMS-10 LOUDSPEAKER CABLES
WITH BELDEN 1502 CABLE (OR EQUIVALENT)
When wiring HMS-10 loudspeaker cables with Belden 1502
cable, use the conventions in Table 3. The red and black
wires in the Belden 1502 cable have a thicker gauge than
the other three wires and should be used for DC power. The
blue, white, and shield wires are shielded together and
should be used for audio.
CAUTION: When wiring HMS-10 loudspeaker
cables, it is extremely important that each pin
be wired correctly. Make sure the 48 V DC from the
external power supply is wired directly (and only) to
the 48 V DC pins on the HMS-10 loudspeaker con-
nector, and that the polarity is observed (negative to
negative, positive to positive) to avoid damage to the
loudspeaker. In addition, make sure that audio pins
are wired correctly; polarity reversals for audio signals
affect system performance.
Belden 1502 Composite Cable
Table 3: Wiring HMS-10 Loudspeaker Cables with Belden 1502
Wire Gauge Gauge
Red DC power, positive (+) 18 AWG
Black DC power, negative (–) 18 AWG
White Balanced audio, positive (+) 22 AWG
Blue Balanced audio, negative (–) 22 AWG
Shield Balanced audio, shield 24 AWG
Red: DC power (+)
Black: DC power (–)
White: audio (+)
Blue: audio (–)
Audio shield
!