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Flexible, competitively priced infrared system, ideal for use in large facilities that have hearing assistance, language interpretation or audio description needs. Two-channel operation provides multi-channel flexibility for independent or stereo operation. Everything you need for installation is in the box.

System Includes

(1) MOD 232 modulator
(1) WIR TX9 DC emitter (black)
(1) TFP 010 power supply
(1) TFP 053 power supply
(2) WCA 013 RCA-to-RCA cables
(2) CNA 007 RCA-to-1/4" adapters
(1) WCA 079 50’ power cable
(1) WCA 084 100’ coax cable
(1) BKT 024 wall/ceiling mount
(1) IDP 008 ADA wall plaque


  • Mic and line inputs
  • Audio indicator LEDs and IR test LED
  • No radio license required
  • 5-year warranty (90 days on accessories)
  • Made in USA

Williams AV WIR TX925: SoundPlus® 2-channel Infrared System IR TRANSMITTER


MOD 232

Size, Weight: 8.5" W x 8.2" D x 1.7" H (21.5 cm x 20.8 cm x 4.4 cm), 3.1 lbs (1.5 kg)
Color: Black epoxy paint with white legends
Rack Mount: 1/2 rack space wide, 1 rack space high, one or two modulators may be mounted in a single IEC rack space with RPK 005 (single) or RPK 006 (double) Rack Mount Kits
Power Supply: Wall Transformer, 24 VAC, 50-60 Hz, 15VA North America: TFP 016, UL/CSA Europe: TFP 027-01, 2-pin Schuko plug, CE UK: TFP 027-02, 3-pin UK plug, CE
Modulation: FM Wideband, +50 kHz deviation, 50 uS pre-emphasis
Carrier Frequency: Channel A: Selectable, 2.3/2.8/3.3/3.8 MHz, Channel B: Selectable, 2.3/2.8/3.3/3.8 MHz
Signal-to-Noise Ratio: More than 60dB
Frequency Response: 30 to 16,000 Hz, +1 dB, -3 dB, electrical response
Total Harmonic Distortion: Less than 2%, electrical response
Audio Processing: Compression (slope) adjustable from 1:1 or 2:1 Switchable compression gain: Moderate: 16dB. Max: 33dB
Auto Carrier Shut-Off: 15-minute timer shuts off carrier when no audio is present (can be disabled)
Power Switch: Two-position push button, ON/OFF
Power Indicator: Green LED
Audio Level Controls: CHA and CHB Input Level, rotary knobs
Audio Indicators: CHA and CHB Audio Level, 10-segment LED’s
Carrier LEDs: 4 green LED carrier “on" indicators per channel (indicates frequency, malfunctions)
Compress Control: 1:1 or 2:1
Input Mix LED: Indicates inputs A and B audio are mixed and transmitted by CHA and CHB off
Stereo LED: Indicates stereo mode
Phones Switch: Selects CH1 or CH2 for phones when not in stereo mode
Phones Output: 1/4" TRS headphone jack. Accepts stereo, mono and any impedance phones.
Infrared Test LED: IR LED for receiver testing, monitoring and audio signal testing.
Power Input: 3-Pin Molex, 24 VAC, 50-60 Hz, 15 VA
Audio Input Jack: CHA and CHB combination XLR/TRS jack
Mic Level: Balanced, Lo-Z, 100 µV min. to 90 mV max., 1 mV nominal, 3kΩ input impedance, supplies switchable simplex power per DIN 45596 for condenser mics
Line Level: Balanced or unbalanced, 21 mV min. to 10V max., 212 mV nominal, 100 kΩ
Audio Line Output Jacks: RCA Jack, CHA and CHB, 500 mV, unbalanced, 100 Ω source impedance, load impedance must be greater than1 kΩ
Configuration Switches: CHA and CHB 8-position DIP switch, selects Mic/Line input, compressor gain, simplex power, discrete or mixed inputs, carrier frequency, channel disable, auto shut-off timer
Baseband Input Jack: BNC, allows mixing with additional MOD 232 Modulator (4CH operation), 100 mV, 50 Ω input impedance, use with MOD 232 or MOD 112 (111), BNC, RG-58 Cable
Baseband Output Jack: Two BNC jacks carry baseband signal, 100 mV/channel, 50 Ω source impedance, for use with WIR TX9 or MOD 232 only
Approvals: CE, FCC, RoHS, WEEE
Operating Requirements: 0-50º C ambient temperature, non-condensing, non-corrosive atmosphere
Warranty: 5 years on modulator*
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