HMS-10 OPERATING INSTRUCTIONS
11
Routing One Input to Four Outputs
To route one audio input to four channel outputs:
■ Set all Link switches to ON.
Routing Two Inputs to Two Outputs Each
To route two audio inputs to two channel outputs each:
1. Set Link switch 3 to OFF and all other switches to ON.
Routing Four Inputs to Four Separate Outputs
To route four audio inputs to four separate channel outputs:
■ Set all Link switches to OFF.
Input Impedance for Linked Channel Inputs
When a Link switch is enabled, the channel input’s unbuf-
fered source signal is transmitted in parallel to each linked
channel output. This causes the channel input’s impedance
(normally 10 kOhms for one HMS-10) to be reduced for each
linked channel output. For example:
■ 1 channel output, 10 kOhm input impedance
■ 2 channel outputs, 5 kOhm input impedance
■ 4 channel outputs, 2500 ohms input impedance
To avoid distortion when linking channel inputs, make sure
the source device can drive the total load impedance of the
linked HMS-10 loudspeakers. The source device must be
capable of delivering a minimum of 16 dBV (6.3 V rms into
600 ohms) to yield the maximum peak SPL over the operat-
ing bandwidth of the loudspeaker.
NOTE: Most source devices are capable of
driving loads no smaller than 10 times their
output impedance. To drive four HMS-10s linked
from a single channel input, the source device should
have an output impedance of approximately
200 ohms or less.
Channel Outputs
The MPS-488P’s eight channel outputs deliver DC power
(48 V DC) and balanced audio to up to eight MM-4XPs or to
up to four HMS-10s. The channel outputs use Phoenix 5-pin
male connectors with three pins for balanced audio (posi-
tive, negative, and shield) and two for DC Power (positive
and negative). These pins are clearly labeled on the
MPS-488
P rear panel. A single composite cable (such as
Belden 1502) wired for both DC power and balanced audio
can be used to connect to each HMS-10.
CAUTION: Because the MPS-488
P can power
a maximum of four HMS-10 loudspeakers, the
HMS-10s should only be connected to channel out-
puts 1, 3, 5, and 7. Do not use the even-numbered
channel outputs.
Link 1 Link 2 Link 3 Link 4 Link 5 Link 6 Link 7
On On On On On On On
Link 1 Link 2 Link 3 Link 4 Link 5 Link 6 Link 7
On On On Off On On On
Link 1 Link 2 Link 3 Link 4 Link 5 Link 6 Link 7
Off Off Off Off Off Off Off
1 23 1111
X
X
X
X
X
X
X
X
X
X
X
X
4678
X
X
5
X
X
X
X
X
X
X
X
1 23 1155
X
X
X
X
X
X
X
X
X
X
X
X
4 5 678
X
X
X
X
X
X
X
X
1 2 13574 5 6837
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
MPS-488P Channel Outputs
