Williams Sound WIR TX75/b User manual

WIR TX75/b
Two-Channel Infrared Transmitter
MAN 166C
Manual and User Guide

2
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Contents
Important Safety Instructions.................................................................................................................................................. 3
CAT-5e Cable Safety ........................................................................................................................................................ 3
Receiver Safety Warnings....................................................................................................................................................... 3
Hearing Safety ................................................................................................................................................................. 3
Battery Safety and Disposal ............................................................................................................................................. 3
Pacemaker Safety ............................................................................................................................................................ 3
Transmitter Safety Warnings............................................................................................................................................. 3
Recycling Instructions ...................................................................................................................................................... 4
System Overview.................................................................................................................................................................... 5
Installation Procedures ........................................................................................................................................................... 6
Determine Coverage Area ................................................................................................................................................ 6
Optional WIR TX75-S Slave Emitter for Additional Coverage............................................................................................. 7
Control Panel ................................................................................................................................................................... 9
Connect Power .............................................................................................................................................................. 10
Connect Audio Source ................................................................................................................................................... 10
Adjust the Audio Level.................................................................................................................................................... 10
Connecting Master and Slave Units................................................................................................................................ 11
WIR TX75 Indicators.......................................................................................................................................................12
Mounting Options ................................................................................................................................................................. 12
Accessories .......................................................................................................................................................................... 12
Troubleshooting .................................................................................................................................................................... 13
Optional Receivers................................................................................................................................................................ 14
Limited Warranty................................................................................................................................................................... 15
SoundPlus® Infrared Transmitter Specications Model WIR TX75 ........................................................................................ 16
SoundPlus® Infrared Transmitter Specications Model WIR TX75-S..................................................................................... 17
WIR TX75 Two-Channel Infrared Transmitter

3
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Important Safety Instructions
Please read and keep these instructions.
CAT-5eCABLE SAFETY
CAUTION!
Do NOT plug the WIR TX75 (master) CAT-5e / RJ45 cable into anything other than the WIR TX75-S slave(s). The TX75
CAT-5e / RJ45 connection is proprietary and is NOT compatible with ethernet or any other RJ45 systems. Failure to
comply with this caution can destroy this or other equipment and will void the warranty.
Receiver Safety Warnings
HEARING SAFETY
CAUTION!
Many Williams Sound receivers are designed to amplify sounds to a high volume level, which could potentially cause hearing
damage if used improperly. To protect your hearing and the hearing of others:
1. Make sure the volume is turned down before putting on the earphone or headphone—only then adjust the volume to a
comfortable level.
2. Set the volume level at the minimum setting that you need to hear.
3. If you experience feedback (a squealing or howling sound), reduce the volume setting and move the microphone away from the
earphone or headphone.
4. Do not allow children or other unauthorized persons access to this product.
BATTERY SAFETY AND DISPOSAL
CAUTION!
Williams Sound receivers are supplied with non-rechargeable alkaline batteries. Do not attempt to recharge non-rechargeable
batteries; they may explode, release dangerous chemicals, cause burns, or cause other serious harm to the user or product.
PACEMAKER SAFETY
CAUTION!
If you have a pacemaker or other medical device, make sure that you are using the Williams Sound receiver in accordance with
safety guidelines established by your physician or the pacemaker/medical device manufacturer.
Transmitter Safety Warnings
WARNING! To reduce the risk of re or electric shock, do not expose the system to rain or moisture. Do not use this
apparatus near water. The system should not be exposed to dripping or splashing, and objects lled with liquids such
as beverages should not be placed on the transmitter or receivers. Clean only with a dry cloth.
CAUTION
RISK OF ELECTRICAL SHOCK — DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO
NOT REMOVE COVER (OR SIDES). NO USER-SERVICABLE
PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.
!AVIS
RIQUE DE CHOC ELECTRIQUE. NE PAS OUVRIR
ATTENTION: POUR RÉDUIRE LE RISQUE DE DÉCHARGE ÉLECTRIQUE, NE
RETIREZ PAS LE COUVERCLE (OU CÔTÉS). IL NE SE TROUVE AL’INTÉRIEUR
AUCUNE PIECE POUVANT ETRE RÉPARÉE PAR L’USAGER. S’A DRESSER A
UN RÉPARATEUR COMPÉTENT.
!

4
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Servicing or attempting to service this device will void the warranty
Refer servicing to qualied personnel. Servicing is required when the system has been damaged in any way: if liquid has been
spilled or objects have fallen into the unit, if the unit has been exposed to moisture, if the unit does not operate normally, or if the
unit has been dropped.
Do not block any ventilation openings. Install in accordance with manufacturer’s instructions.
Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus that produces heat.
Use only attachments/accessories specied by the manufacturer.
Unplug the transmitter during lightning storms or when unused for long periods of time.
Be advised that different operating voltages require the use of different types of line cord and attachment plugs. Check the voltage
in your area and use the correct type.
Use only the power supply provided by Williams Sound. Other power supplies may have similar specications, but may not
be equivalent in emissions ratings, in-rush current, etc. Use of an unapproved power supply may leave the device partially or
completely inoperable, and will void the warranty.
This apparatus has been designed with class-1 construction and must be connected to a main socket outlet with a protective
ground connection (the third grounding prong).
Protect the power cord from being walked on or pinched, particularly at plugs, receptacles, and near the power jack on the
transmitter.
This apparatus must be grounded.
The MAINS plug or an appliance coupler is used as the disconnect device, so the disconnect device should remain readily
operable.
For Customers in The United States
WARNING: Use a three-wire grounding-type line cord as is supplied with the product. Do not defeat the safety
purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A
grounding type plug has two blades and a third grounding prong. The wide blade or the third prong is provided for
your safety. If the provided plug does not t into your outlet, consult an electrician for replacement of the obsolete
outlet. This equipment has been tested and found to comply with the limits for Class B digital device, pursuant to part
15 of the FCC rules.
For Customers in Canada
This Class B digital device meets all requirements of the Canadian Interference-causing Equipment Regulations.
Cet appareil numérique de la classe B respecte toutes les exigencies du Règlement sur le matériel brouilleur du Canada.
Recycling Instructions
Help Williams Sound protect the environment. Please take the time to dispose of your equipment properly.
Product Recycling for Customers in the European Union:
Please do NOT dispose of your Williams Sound equipment in the household trash. Take the equipment to a electronics
recycling center, or return the product to the factory for proper disposal.

5
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
System Overview
The WIR TX75 two-channel infrared transmitter combines infrared modulator and emitter technology into a single mountable
enclosure—which reduces operating costs, eliminates the need for rack space and eases set-up.
The WIR TX75 is ideal for high-quality audio programs such as music, theater and audio description. The WIR TX75 will accept
any line level, balanced or unbalanced audio inputs. Infrared receivers detect the transmission and convert the light signals back
into audio signals. The 2.3/2.8 MHz (or 3.3/3.8 MHz for TX75b) operating frequencies minimize high-efciency lighting interference.
Up to two slave emitters can be added for additional coverage. Power, baseband, and digital data are fed to the slave emitters via
a single CAT-5e cable for each emitter. No additional cables are required.
No FCC license or radio approval is required with this equipment. It can be used anywhere in the world.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15
of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency
energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to
radio communications. Operation of this equipment in a residential area may cause interference in which case the user
will be required to correct the interference at his own expense.
NOTE: A PLASMA MONITOR OR TELEVISION CAN DEGRADE THE AUDIO QUALITY OF THE WIR TX75 TRANSMITTER. FOR
BEST PERFORMANCE, THE TRANSMITTER SHOULD BE POSITIONED AS FAR AWAY AS POSSIBLE FROM ANY
PLASMA MONITOR OR TELEVISION.

6
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Installation Procedures
Determine Coverage Area
When using the WIR TX75 transmitter in single-channel mode with the RX22-4 receiver, the system coverage area will exceed
5000 ft² (185 m²). WIR TX75 units automatically adjust to give the best coverage area possible in both 1-channel and 2-channel
modes.
Figure 1 illustrates typical coverage pattern for the TX75. This can be affected by direct/indirect sunlight, reections on walls and
room construction.
Reections of the infrared light from walls, ceilings, and oors may change these patterns.
Important: Remember to point the transmitter towards the listening audience.
Remember: Most objects block infrared light. The transmitter cannot be concealed behind walls, glass, curtains, etc.
These patterns are the direct radiation pattern. The infrared radiation does not drop to zero outside the illustrated patterns; it
decreases. It still may be useable at a greater distance, depending on the receiver sensitivity and the reective characteristics of
the room. Reections of the infrared light from walls, ceilings, and oors may change these patterns.
The TX75 and TX75-S can be operated with or without the faceplate, if desired. The faceplate can be removed and painted to
match room decor. Lightly sand faceplate with 400 grit sandpaper apply primer and two coats of nal color. Do not paint the
infrared lens behind the faceplate of the TX75.
Figure 1: Receiver coverage area with WIR TX75 transmitter OR WIR TX75-S slave emitter in single channel mode.
0
10
20
30
40
RX22-4 RECEIVER
RX18 RECEIVER RX15-2 RECEIVER
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170
A157
FEET

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WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Optional WIR TX75-S Emitter for Additional Coverage
For larger facilities, additional emitters can be used to increase the total coverage area. The WIR TX75 is capable of driving two
WIR TX75-S slave emitters. Power, baseband and digital data bus are fed via CAT-5e cable to each TX75-S slave.
Figure 2: overlapping illumination patterns to cover larger listening areas.
A158
Figure 3: coverage area with second emitter added to same emission point (50% increase)
0
10
20
30
40
50
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220
A156
230
FEET
MASTER ONLY MASTER + SLAVE

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WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Figure 5: WIR TX75 master and two slaves at an angle of 35° to each other.
0
20
40
60
80100
120
140160
180 A159
Control Panel
Figure 6: WIR TX75 master rear view
POWER IN MIC CHANNEL
SELECTOR
LINE IN BALANCED/
UNBALANCED SELECTOR
TX75 BUS
OUT TO
SLAVE (1)
TX75 BUS
OUT TO
SLAVE (2)
MIC IN
CH 1 AUDIO
LEVEL INDICATOR
(YELLOW)
CH 2 AUDIO
LEVEL INDICATOR
(YELLOW)
SLAVE TRANSMIT
POWER INDICATOR
(YELLOW)
SLAVE POWER
INDICATOR
(GREEN)
INDICATOR
LIGHTS (ON/OFF)
MIC
ADJUSTMENT
POWER
INDICATOR
A139
RCA IN RCA IN
(2.3) TX-75 (2.8)
(3.3) TX-75b (3.8)

9
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Connect Power
WARNING: MAINS VOLTAGE MUST NOT FALL BELOW 100VAC, 0R SYSTEM PERFORMANCE WILL BE
GREATLY REDUCED. UNIT MAY ENTER RESET MODE UNTIL POWER IS RESTORED.
1. Plug the power supply output cord into “Power In” on the WIR TX75.
2. Attach a line cord to the power supply.
3. Plug the power supply into the AC outlet. TFP 046: 100-240 VAC IN, 50 / 60 Hz.
This system is designed for class 2, low-voltage wiring. Always follow local electrical codes when using low-voltage wiring.
Green Power
The WIR TX75 is equipped with a sleep/power save feature. If no audio is present on either channel for three minutes, the
transmitter will automatically go into sleep/power save mode. This mode decreases power consumption by 80 percent. Units
will automatically start up when audio is activated. This sleep/power save feature can be disabled. Contact Williams Sound for
instructions.
On power up, the WIR TX75 performs a self-test to detect damage due to shipping, handling, tampering or incorrect operation.
If any failure is present, green indicator lights will blink. See WIR TX75 Indicators table on page 12 for instructions on how to read
indicator lights.
Connect Audio Source
Automatic Channel Detection/ Shutdown
The WIR TX75 offers two carrier frequencies: Ch 1 (2.3 MHz) and Ch 2 (2.8 MHz). The WIR TX75boffers two different carrier
frequencies: Ch 1 (3.3 MHz) and Ch 2 (3.8 MHz). Either unit automatically detects the presence of audio on the microphone and RCA
audio inputs, and transmits on either/both channels when an audio signal is present on that channel. If audio is present on both the
microphone and RCA jack for a given channel, the audio signals will be mixed.
When no audio signal is present on a channel for three minutes, the TX75 will shut down that channel. Operating the WIR TX75 in single-
channel mode provides a 40 percent increase in range over two-channel mode.
Line Level Source:
The WIR TX75 will accept line level, balanced or unbalanced audio inputs. Select the frequency(ies) you wish to transmit on and
connect your audio source(s) to the appropriate jack(s). If your audio inputs are balanced, use the switch to select “bal”. If your
audio inputs are unbalanced, use the switch to select “unbal”. See gure 7 for balanced wiring conguration.
Microphone Source
Plug an electret microphone into the 3.5mm “Mic In” jack (MIC 027, MIC 100, or MIC 090). To assign the microphone to Ch 1
use the Mic Channel Switch to select “2.3” (or “3.3” MHz on the TX-75b). To assign the microphone to Ch 2 use the Mic Channel
Switch to select “2.8” (or “3.8” MHz on the TX-75b).
Figure 7: Balanced line out (XLR) to WIR TX75 line input (RCA) cable
1 23
FEMALE XLR
RED (IN PHASE)
RED RCA
(TIP=IN PHASE)
2 CONDUCTOR
WITH SHIELD
BLACK (SIGNAL)
BLACK
TO TX75
SHIELD NOT CONNECTED
ON TX75 CABLE END
1= SHIELD, 2= RED (SIGNAL IN PHASE), 3=BLACK (SIGNAL)
A160

10
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Adjust the Audio Level
Line Level Source
After an audio signal has been connected to the transmitter, adjust the audio source gain until the WIR TX75 audio-level indicator
for that channel blinks periodically.
Microphone Source
Speak into the microphone from a normal distance and at a natural voice level. Use the microphone gain adjustment on the TX75
to set the gain to the point where the audio level indicator on the selected channel blinks periodically. If the audio level indicator is
always on or on most of the time, the level is too high. If the audio level indicator is never on, the level is too low.
Connecting Master and Slave Units
Connect all WIR TX75 master and slave(s) units together using CAT-5e cables, the “to slave” jacks on the master, and the “Master
In” jack on the slave(s). For systems with no slave units, the CAT-5e cables and “to slave” jacks are not used. For systems with one
slave unit, either “out 1” or “out 2” may be used.
When a cable is plugged into a “to slave” jack, the master unit will automatically detect mis-wired, intermittent or bad CAT-5e
cables; a yellow status indicator light will blink on that channel’s “to slave” jack to indicate any problem. See WIR TX75 Indicators
table on page 12 for instructions on how to read indicator lights.
The WIR TX75 automatically detects when slave units are plugged in, establishes a data link to verify operation, monitors status,
and enables baseband output to the slave emitter(s).
Once a master and slave unit are connected, the yellow and green indicators located on the “to slave” and “Master In” jacks mimic
each other. This allows the user to know the status of the entire system by simply looking at the indicators on the back of the
master unit. A switch is provided to turn off all indicator lights AFTER initial set-up, to allow for less conspicuous operation.
Note: The WIR TX75 will automatically detect and adjust for differences in CAT-5e cable length. Matching cable lengths to the
slaves is not necessary. Cable length up to 100 feet may be used.
Figure 8: Connecting a WIR TX75 transmitter to two WIR TX75-S slave emitters
POWER
RCAMIC CAT5E
TX75 MASTER
TX75S SLAVE #1
(OPTIONAL)
AUDIO
SOURCE
MICROPHONE
(ELECTRET)
AC POWER
SOURCE
TX75S SLAVE #2
(OPTIONAL)
A161

11
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Troubleshooting
For easier troubleshooting, the TX75 units are equipped with a series of self-tests and indications. Please see WIR TX75 indicator
lights table on page 12 to aid in troubleshooting.
The WIR TX75 “Power Indicator” is not lit:
• Make sure the power supply is plugged into the transmitter and any remote power switch is on.
• Set the “Indicators” switch on the back panel to “On”.
• Make sure the electrical outlet is on.
• Make sure the 48 VDC power supply is working.
The WIR TX75’s Ch1 or Ch2 “Audio-level Indicator” does not light:
• Make sure the WIR TX75 is plugged in.
• Set the “Indicators” switch on the back panel to “On”.
• Make sure the audio input is connected properly. See page 10.
• Make sure an active and adequate level audio signal is being sent to the WIR TX75 transmitter.
No Sound through Receivers:
• Check to make sure the receiver is operating on the same frequency as the transmitter.
• If some of the receivers work but others don’t, check for bad batteries or earphones.
• If none of the receivers work, check to see if the power and audio input cables are connected to the transmitter. Verify that the
“Power Indicator” is on steady, and ch1 or ch2 “audio-level indicator” blinks periodically.
• Check to see if the transmitter is connected properly to the audio source. The audio-level indicators should ash on channels that
have audio.
• Make certain the transmitter is not covered by objects which would block infrared light.
Sound Through the Receivers is Weak and Noisy:
• Try adjusting the audio input level (see page 10). If the signal sounds okay, you may need to reposition the transmitter beam or add
additional TX75-S slave emitters to the WIR TX75 system.
Buzzing or Humming Noise in Sound System:
• Check for ground loops or noise on the input signal.
• Check to make sure the “balanced / unbalanced” switch is in the correct position.
If these instructions do not address your problem or the issue persists, please call your authorized Williams Sound dealer or
representative.

12
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
WIR TX75 Indicator lights
INDICATOR ON UNIT STATE DESCRIPTION
Power Indicator – Green
(round or rectangle) Master or Slave
On steady Unit is powered and actively transmitting
Fade-on, Fade-off… (continuous) Unit is powered and in sleep/power-save mode (no audio signal
detected, unit is not transmitting)
Fast blink (continuous) Self test has detected an internal failure on this unit
Audio Level Indicators – Yellow
round (ch1 or ch2) Master
Blinking periodically Audio is present on this channel and is set to the optimum level
On steady (or most of the time) Audio is present on this channel but the level is too high
Off Audio is not present OR audio level is too low on this channel
Slave Status Indicator – Yellow
(rectangle) Master or Slave
On steady Carrier signal is being sent to this slave
Off No carrier signal is being sent to this slave
Fast blink (continuous) Self test has detected a CAT-5e cable failure between the master
and this slave unit
All indicators Master or Slave
On for 2 seconds, Off for 1
second, resumes normal states
Initial power-on sequence OR unit has reset
On for 2 seconds, Off for 1
second… (continuous)
Unit is continuously resetting - may be due to a low voltage supply
condition (In Master: bad power supply. In Slave: bad CAT-5e cable
or CAT-5e cable is too long)
NOTE: The indicator lights can all be turned off AFTER initial set-up to allow for less conspicuous operation.
Mounting Options
BKT 024 - Universal wall / ceiling mount (included)
MLB 003 - Linking Bar - 2 1/2” bar with 1/4” - 20 threaded male connectors on both ends (optional), for stacking master and
slave together.
The TX75 can be mounted on any camera tripod stands with a 1/4” - 20 threaded connector.
The TX75 and TX75-S can be operated with or without the faceplate, if desired. The faceplate can be removed and painted to
match room decor. Lightly sand faceplate with 400 grit sandpaper apply primer and two coats of nal color. Do not paint the
infrared lens behind the faceplate of the TX75.
Accessories
MIC 027 Hand-held unidirectional microphone
MIC 090 Lavaliere microphone
MIC 100 Rear-wear headset microphone
PLE 078 SIL - Silver Faceplate (included)
PLE 078 WHT - White Faceplate (optional)
WCA 078 - 3’ Stereo RCA cable
WCA 096 - 12” CAT-5e cable for connection to slave emitter (optional)
WCA 091 - 25’ CAT-5e cable for connection to slave emitter (optional)

13
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Optional Receivers
WIR RX15-2 Receiver:
INFRARED
SENSOR
BATTERY
COVER
POWER/CHANNEL
SWITCH
POWER/
CHANNEL
INDICATOR
A169
AUDIO INPUT JACK
MONITOR/MUTE
BUTTON
VOLUME
KNOB
RIGHTLEFT
MUTE
OFF
ON/OFF
VOLUME SWITCH
A162
EARPHONE
JACK
"ON"
INDICATOR
CHANNEL
SELECTOR
WIR RX18 Receiver
WIR RX22-4 Receiver:
BATTERY
(BAT AP07D)
A163
VOLUME
CONTROL
FREQUENCY SELECTION SWITCH
2.3 MHz, STEREO, 2.8 MHz
BALANCE
CONTROL
NOTE: On the RX22-4, channel 1=2.3 MHz, channel 2=2.8 MHz, channel 3=3.3 MHz, and channel 4=3.8 MHz.

14
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Infrared Transmitter Specications
Model WIR TX75 (Master)
Dimensions, Weight: 10.0" W (25.4 cm) x 3.1" D (7.9 cm) x 1.5" H (3.8 cm) w/o faceplate or 2.5" H (6.4 cm) w/faceplate, 0.6 lbs (0.3kg)
Color: Black with silver colored silk screen and silver colored faceplate
Optional: white colored faceplate
Power Supply: Desktop style international power supply with IEC line cord, 100-240 VAC input, 50-60Hz, 24W; 48VDC output
DC Power Input: 2.5mm ID barrel connector, 48 VDC, 0.4A center positive
Power Indicator: Green LED
Sleep/Power Save Mode: Shuts off carrier when no audio is present for 3 minutes
Modulation: FM Wideband, ±50kHz deviation max, 50 μS pre-emphasis
Carrier Frequencies: TX-75: 2.3MHz (Ch1) and 2.8MHz (Ch2).
TX-75b: 3.3MHz (Ch1) and 3.8MHz (Ch2).
Default at power on = carriers off. Carriers are automatically enabled upon presence of audio.
Emitter IR Power: 0.7 W
Master Only Coverage Area
(minimum, 1-Ch mode):
5,000 sq. ft in single-channel mode with the RX22-4 receiver (464 sq. m)
3,000 sq. ft in single-channel mode with the RX15-2 receiver (279 sq. m)
2,000 sq. ft in single-channel mode with the RX18 receiver (186 sq. m)
Audio Inputs / Controls: Line inputs: RCA jack for Ch1 and Ch2 accept line level, balanced or unbalanced audio
Line in balanced/unbalanced switch: selects balanced or unbalanced line level audio for RCA jacks
Microphone input: 3.5 mm, stereo jack with signal and bias connected to tip, electret microphone compatible (4 VDC bias supply with 2.7k ohm
series resistor)
Microphone gain adjust: Rotary potentiometer
Microphone channel switch: selects microphone input to Ch1 or Ch2
Audio indicators: Yellow LED blinks at nominal audio level. One per channel
Indicators On/Off: 2-position switch turns on/off indicator lights
“to slave” Output/Input: (2) 8p8c RJ45 connectors output 48VDC 0.4A power, baseband RF and a bi-directional RS-485 bus for control and status
communications
Slave Status Indicators
(on “to slave” jacks):
Green: Power/Unit Status
Yellow: Transmit/Cable Status
Signal-to-Noise Ratio: 70 dB, (line input)
Frequency Response: 95Hz to 17.6kHz, -3dB re 1kHz (line inputs)
125Hz to 17.0KHz, -3dB re 1kHz (microphone input)
Total Harmonic Distortion: <1% (1 kHz, nominal deviation, line or microphone input)
Operating Requirements: 0-50° C (32°-122°F)
Mounting Kit: Wall or Ceiling mount: BKT 024 Omnidirectional mount
Optional: slave linking bar (MLB 003)
Warranty: 2 Years
Approvals: CE, C-tick, FCC, Industry Canada, WEEE, RoHS, CB Scheme
Compatible Receivers: WIR RX22-4, WIR RX18, WIR RX15-2
NOTE: Specications subject to change without notice.
Visit our website for the latest specications and publications: www.williamssound.com

15
WIR TX75 Two-Channel Infrared Transmitter
MAN 166C
Infrared Emitter Specications
Model WIR TX75-S (Slave)
Dimensions, Weight: 10.0” W (25.4 cm) x 3.1” D (7.9 cm) x 1.5” H (3.8 cm) w/o faceplate or 2.5” H (6.4 cm) w/faceplate, 0.6 lbs (0.3kg)
Color: Black with silver colored silk screen and silver colored faceplate
Optional: white colored faceplate
Sleep/Power Save Mode: Shuts off carrier when no audio is present for 3 minutes
Modulation: FM Wideband, ±50kHz deviation max, 50 μS pre-emphasis
Carrier Frequencies: TX-75: 2.3MHz (Ch1) and 2.8MHz (Ch2).
TX-75b: 3.3MHz (Ch1) and 3.8MHz (Ch2).
Default at power on = carriers off. Carriers are automatically enabled upon presence of audio.
Emitter IR Power: 0.7 W
Slave Coverage Area
(minimum, 1-ch mode):
Note: Slave emitter cannot be used without a master transmitter, but if the slave emitter is aimed so that its coverage area does
not overlap that of the master, on its own it will provide:
5,000 sq. ft in single-channel mode with the RX22-4 receiver (464 sq. m)
3,000 sq. ft in single-channel mode with the RX15-2 receiver (279 sq. m)
2,000 sq. ft in single-channel mode with the RX18 receiver (186 sq. m)
Master + Slave Coverage Area
(minimum, 1-ch mode)
If slave transmitters are aimed to maximize coverage area (so that their coverage areas minimally overlap that of the master):
10,000 sq. ft in single channel mode with the RX22-4, a master and (1) slave transmitter (929 sq. m)
15,000 sq. ft in single channel mode with the RX22-4, a master and (2) slave transmitters (1,393 sq. m)
Indicators On/Off: 2-position switch turns on/off indicator lights
Signal-to-Noise Ratio: 70 dB, (line input)
Frequency Response: 95Hz to 17.6kHz, -3dB re 1kHz (line input)
125Hz to 17.0kHz, -3dB re 1kHz (microphone input)
Total Harmonic Distortion: <1% (1 kHz, nominal deviation, line or microphone input)
From Master Input 8p8c RJ45 connector input provides 48VDC 0.4A power, baseband RF, and a bi-directional RS-485 bus for control and status
communications.
Slave Extension Cable: CAT-5e (or better) cable, maximum 100’ length, with RJ-45 8P8C male connector on each end, TIA568B
Slave Status Indicators
(on “to slave” jacks):
Green: Power/Unit Status
Yellow: Transmit/Cable Status
Operating Requirements: 0-50° C (32°-122°F)
Mounting Kit: Wall or Ceiling mount: BKT 024 Omnidirectional mount
Optional: slave linking bar (MLB 003)
Warranty: 2 Years
Approvals: CE, C-tick, FCC, Industry Canada, WEEE, RoHS, CB Scheme
Compatible Receivers: WIR RX22-4, WIR RX18, WIR RX15-2
NOTE: Specications subject to change without notice.
Visit our website for the latest specications and publications: www.williamssound.com

MAN 166C
WIR TX75 Two-Channel Infrared Transmitter
Limited Warranty
Williams Sound products are engineered, designed, and manufactured under carefully controlled conditions to provide many years
of reliable service. Williams Sound warrants the WIR TX75 infrared listening system against defects in materials and workmanship
for two (2) years. During the rst two years from the purchase date, we will promptly repair or replace the WIR TX75 infrared
listening system.
Microphones, earphones, headphones, batteries, chargers, cables, carry cases, and all other accessory products carry a 90-day
warranty.
WILLIAMS SOUND HAS NO CONTROL OVER THE CONDITIONS UNDER WHICH THIS PRODUCT IS USED. WILLIAMS
SOUND, THEREFORE, DISCLAIMS ALL WARRANTIES NOT SET FORTH ABOVE, BOTH EXPRESS AND IMPLIED, WITH
RESPECT TO THE WIR TX75 INFRARED LISTENING SYSTEM, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WILLIAMS SOUND SHALL NOT BE LIABLE TO ANY
PERSON OR ENTITY FOR ANY MEDICAL EXPENSES OR ANY DIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES
CAUSED BY ANY USE, DEFECT, FAILURE OR MALFUNCTIONING OF THE PRODUCT, WHETHER A CLAIM FOR SUCH
DAMAGES IS BASED UPON WARRANTY, CONTRACT, TORT OR OTHERWISE, THE SOLE REMEDY FOR ANY DEFECT,
FAILURE OR MALFUNCTION OF THE PRODUCTS REPLACEMENT OF THE PRODUCT. NO PERSON HAS ANY AUTHORITY
TO BIND WILLIAMS SOUND TO ANY REPRESENTATION OR WARRANTY WITH RESPECT TO THE WIR TX75 INFRARED
LISTENING SYSTEM. UNAUTHORIZED REPAIRS OR MODIFICATIONS WILL VOID THE WARRANTY.
The exclusions and limitations set out above are not intended to, and should not be construed so as to contravene mandatory
provisions of applicable law. If any part or term of this Disclaimer of Warranty is held to be illegal, unenforceable, or in conict with
applicable law by a court of competent jurisdiction, the validity of the remaining portions of this Disclaimer of Warranty shall not be
affected, and all rights and obligations shall be construed and enforced as if this Limited Warranty did not contain the particular
part or term held to be invalid.
If you experience difculty with your system, call toll-free for customer assistance: 1-800-843-3544 (U.S.A.) or [phone]
(outside the U.S.A.)
If it is necessary to return the system for service, your Customer Service Representative will give you a Return Authorization
Number (RA) and shipping instructions.
Pack the system carefully and send it to:
Williams Sound
Attn: Repair Dept.
10300 Valley View Road
Eden Prairie, MN 55344 USA
Your warranty becomes effective the date you purchase your system. If your sales receipt is not available, the date code on the
product will determine your warranty status.
©2012 Williams Sound • All Rights Reserved
10300 Valley View Rd • Eden Prairie, MN 55344
800-328-6190 / 952-943-2252 • FAX: [phone]
www.williamssound.com