12
IR Plus Assistive Listening System
Audio Source Connections
The IR M1 Modulator will accept the following audio sources:
1. Balanced Microphone with or without 12-volt phantom power (DIN 45596) on a 3-pin (XLR) connector.
2. Balanced/Unbalanced microphone with or without phantom power on 1/4 inch (TRS) jack
3. Balanced/Unbalanced Line on a 3-pin (XLR) connector.
4. Balanced/Unbalanced Line on 1/4 inch (TRS) jack.
5. Dante on an RJ-45 jack (optional).
WARNING:
The IR + is not designed to accept 70 volt speaker signals! This may result in damage to your system. The sound
source should come directly from the system mixer or digital source as a low-level or unprocessed signal.
BALANCED LINE USING 3–PIN CONNECTOR
IN PHASE
1
2
3
3 PIN CONNECTOR
A108
UNBALANCED LINE USING 3–PIN CONNECTOR
1
2
3
3 PIN CONNECTOR
A105
BALANCED LINE USING 1/4" CONNECTOR
IN PHASE
A106
UNBALANCED LINE USING 1/4" CONNECTOR
A107
4.7 K
4.7 K
SOURCE A
SOURCE B
CONNECTING TO A MULTI-CHANNEL OR STEREO SOURCE
A109
Multi-Channel Sources
By constructing a simple resistive mixer, stereo (or 3 channel) sources can be connected to the IR +. Additional channels can be
accommodated by adding a resistor for each source.
Note: The Dante audio input will automatically mix the left and right channels�
Avoiding Hum in the Audio (as a Result of a Ground Loop)
A hum created by a ground loop can often be eliminated by connecting a capacitor in series with the audio line shield to the
modulator’s ground. This method also maintains good radio frequency (RF) shielding. Determining the effectiveness of this method
for your installation usually requires some experimentation.
IN PHASE
1
2
3
3-PIN
CONNECTOR
BREAKING A GROUND LOOP WHEN
CONNECTING TO A UNBALANCED LINE
BREAKING A GROUND LOOP WHEN
CONNECTING TO A BALANCED LINE
.01 uF CERAMIC DISC
CAPACITOR
.01 uF CERAMIC
DISC CAPACITOR
A110