Sony MDRRF985RK User Manual

MDR-RF985RK(UC2/AU2) [US, FR] 4-429-926-12 (1)

To reduce the risk of fire or electric shock, do not expose this 

apparatus to dripping or splashing, and do not place objects 

filled with liquids, such as vases, on the apparatus.

Do not expose the batteries (battery pack or batteries installed) 

to excessive heat such as sunshine, fire or the like for a long time.

To avoid electrical shock, do not open the cabinet. Refer 

servicing to qualified personnel only.

Do not install the appliance in a confined space, such as a 

bookcase or built-in cabinet.

As the main plug of AC power adaptor is used to disconnect the 

AC power adaptor from the mains, connect it to an easily 

accessible AC outlet. Should you notice an abnormality in it, 

disconnect it from the AC outlet immediately.

Excessive sound pressure from earphones and headphones can 

cause hearing loss.

You are cautioned that any changes or modifications not 

expressly approved in this manual could void your authority to 

operate this equipment.

If you have any questions about this product, you may call: 

Sony Customer Information Services Center 

1-800-222-7669 or http://www.sony.com/

Trade Name: 

SONY

Model No.: 

MDR-RF985R

 

(Headphones Unit)

Responsible Party:  Sony Electronics Inc.

Address: 

16530 Via Esprillo, San Diego, CA 92127 

USA

Telephone No.: 

858-942-2230

This device complies with Part 15 of the FCC Rules. Operation 

is subject to the following two conditions: (1) this device may 

not cause harmful interference, and (2) this device must 

accept any interference received, including interference that 

may cause undesired operation.

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 in a residential 

installation. This equipment generates, uses and can radiate 

radio frequency energy and, if not installed and used in 

accordance with the instructions, may cause harmful 

interference to radio communications.

However, there is no guarantee that interference will not occur 

in a particular installation. If this equipment does cause harmful 

interference to radio or television reception, which can be 

determined by turning the equipment off and on, the user is 

encouraged to try to correct the interference by one or more of 

the following measures:

Reorient or relocate the receiving antenna.

Increase the separation between the equipment and receiver.

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Connect the equipment into an outlet on a circuit different 

from that to which the receiver is connected.

Consult the dealer or an experienced radio/ TV technician for 

help.

This device complies with Industry Canada licence-exempt RSS 

standard(s). Operation is subject to the following two conditions: 

(1) this device may not cause interference, and (2) this device 

must accept any interference, including interference that may 

cause undesired operation of the device.

Lithium-Ion batteries are recyclable.

You can help preserve our environment by 

returning your used rechargeable batteries to 

the collection and recycling location nearest 

you.

For more information regarding recycling of rechargeable 

batteries, call toll free 1-800-822-8837, or visit 

http://www.rbrc.org/ 

Caution: Do not handle damaged or leaking Lithium-Ion 

batteries.

RF stereo transmitter  

TMR-RF985R (1)

Wireless stereo headphones 

MDR-RF985R (1)

AC adaptor (1)

Connecting cable (stereo mini 

plug  pin plug × 2), 1 m (1)

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When the transmitter’s contact pins meet the headphones’ 

contact points, the CHG indicator lights up red. If they do not 

meet, the indicator will not light up. Confirm that the 

headphones make a “click” sound when you put them on the 

transmitter. When the headphones are correctly placed on the 

transmitter, the upper surface of the headphones becomes level 

with the transmitter.

The CHG indicator turns off when charging is complete.

3.5 hours

2)

25 hours

3)

1)  at 1 kHz, 0.1 mW + 0.1 mW output

2)  hours required to fully charge an empty battery

3)  Time may vary, depending on the temperature or conditions 

of use.

Place the headphones on the transmitter after use. The CHG 

indicator lights up, then charging starts.

When charging is complete, there is no need to remove the 

headphones from the transmitter.

To check the remaining battery charge of the headphones, turn 

on the headphones, and check the power indicator near the 

POWER switch. The battery is still serviceable when the indicator 

lights up green.

Charge the headphones if the power indicator turns off, dims, 

flashes, or the sound becomes distorted or noisy.

Insert the AC adaptor plug firmly.

Be sure to use the supplied AC adaptor. Using AC adaptors 

with different plug polarity or other characteristics can cause 

product failure.

Unified 

polarity plug

The battery capacity may decrease if the headphones are 

turned on and placed on the transmitter with the AC adaptor 

disconnected.

The transmitter automatically turns off while charging the 

headphones.

If the headphones are used outside the recommended 

temperature range, the CHG indicator flashes and charging 

stops. Charge in an environmental temperature of between 

5°C and 35°C (between 41 °F and 95 °F).

If you haven’t used the headphones for a long period of time, 

the life of the rechargeable battery may become short. This will 

improve when you repeat the charging and discharging 

process several times.

When the battery life reduces to half, this may be the end of 

battery lifetime. For how to change batteries, consult your 

place of purchase or a Sony dealer.

Do not store the headphones in hot places for a long period of 

time. When storing them for more than a year, charge the 

battery once a year to prevent over discharge.

Do not touch the contact pins of the transmitter. If the contact 

pins become dirty, charging may not be possible.

Charging may not be completed if the transmitter’s contact 

pins and headphones’ contact points are dusty. Wipe them 

with a cotton bud, etc.

If you connect the transmitter to the headphone jack of the 

A/V component, set the volume of the A/V component as high 

as possible but not so high that the audio signal becomes 

distorted.

When watching videos, be careful not to raise the volume too 

high in quiet scenes. You may hurt your ears when a loud 

scene is played.

This system utilizes very high frequency signals in the 900 MHz 

band so the receiving performance may deteriorate due to the 

surroundings. The following examples illustrate conditions that 

may reduce the reception range or cause interference.

Inside a building with walls containing steel beams

An area with many steel file cabinets, etc.

An area with many electrical appliances capable of generating 

electromagnetic fields

The transmitter is placed on a metal instrument.

An area facing a roadway

Noise or interfering signals exist in the surroundings due to 

radio transceivers in trucks, etc.

Noise or interfering signals exist in the surroundings owing to 

wireless communication systems installed along roadways.

The optimum distance is up to approximately 45 m (150 ft) 

without the system picking up some interference. However, the 

distance may vary depending on the surroundings and 

environment.

If the system picks up some noise within the above mentioned 

distance, reduce the distance between the transmitter and the 

headphones, or select another channel.

When you use the headphones inside the effective area of the 

transmitter, the transmitter can be placed in any direction from 

the listener.

Even within the signal reception area, there are some spots 

(dead spots) where the RF signal cannot be received. This 

characteristic is inherent to RF signals, and does not indicate 

malfunction. By slightly moving the transmitter, location of the 

dead spot can be changed.

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The earpads are replaceable. If the earpads become dirty or 

worn out, replace them as illustrated below. The earpads are not 

commercially available. You can order replacements from the 

store where you purchased this system, or at your nearest Sony 

dealer.

Remove the old earpad by pulling it out of the groove on the 

housing.

Place the new earpad on the driver unit. 
Hang the edge of the earpad on one side of the driver unit’s 

groove edge, then turn the edge of earpad around the driver 

unit as illustrated below.

When the earpad is securely inserted into the groove, adjust 

the earpad to the vertical position.

If you run into any problems using this system, use the following 

checklist. Should any problem persist, consult your nearest Sony 

dealer.

Turn on the headphones.

Check the connection of the A/V component or the AC 

adaptor.

Check that the A/V component is turned on.

If you connect the transmitter to an A/V component using the 

headphone jack, raise the volume level on the connected A/V 

component within the range where the sound is not distorted.

Change the radio frequency with the CHANNEL selector on the 

transmitter, then press the AUTO TUNING button on the right 

housing of the headphones.

Use the headphones near the transmitter, or change the 

position of the transmitter.

Charge the headphones. If the power indicator is still off after 

charging, take the headphones to a Sony dealer.

Raise the headphone volume.

Charge the headphones. If the power indicator is still off after 

charging, take the headphones to a Sony dealer.

Use the headphones near the transmitter, or change the 

position of the transmitter.

Do not place the transmitter on a metallic table.

If you connect the transmitter to an A/V component using the 

headphone jack, lower the volume level on the connected A/V 

component within the range where the sound is not distorted.

Change the radio frequency with the CHANNEL selector switch 

on the transmitter, then set to the same radio frequency with 

the AUTO TUNING button on the right housing of the 

headphones.

If you connect the transmitter to an A/V component using the 

headphone jack, raise the volume level on the connected A/V 

component within the range where the sound is not distorted.

Charge the headphones. If the power indicator is still off after 

charging, take the headphones to a Sony dealer.

Do not place the transmitter on a metallic table.

Use the headphones near the transmitter.

The transmitter turns off if no signal or low signal is input for 4 

minutes. If you connect the transmitter to an A/V component 

using the headphone jack, raise the volume level on the 

connected A/V component within the range where the sound 

is not distorted.

Put the headphones on the transmitter correctly so that the 

CHG indicator lights up.

The transmitter’s contact pins and headphones’ contact points 

are dusty.  Wipe them with a cotton bud, etc.

You cannot charge while the CHG indicator flashes. Charge in 

an environmental temperature of between 5°C and 35°C 

(between 41 °F and 95 °F).

Check that the AC adaptor is connected to the transmitter.

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If the transmitter is not to be used for a long period of time, 

disconnect the AC adaptor from the AC outlet by holding the 

plug. Do not pull on the cord.

Do not leave this system in a location subject to direct 

sunlight, heat or moisture.

This system is guaranteed for use in the temperature range of 

5 °C to 35 °C (41 °F to 95 °F).

You may hear some noise when you disconnect the AC 

adaptor from the transmitter before taking off the 

headphones.

Avoid exposure to temperature extremes, direct sunlight, 

moisture, sand, dust or mechanical shock.

Avoid using headphones at high volume. Hearing experts advise 

against continuous, loud and extended play. If you experience a 

ringing in your ears, lower the volume or discontinue use.

Keep the volume at a moderate level. This will allow you to hear 

outside sounds and to be considerate to the people around you.

If you have any questions or problems concerning the system 

that are not covered in this manual, please consult your nearest 

Sony dealer.

Be sure to bring the headphones and the transmitter to the Sony 

dealer when requiring repair work.

Thank you for purchasing the Sony MDR-RF985RK Wireless 

Stereo Headphone System. Before operating the unit, please 

read this manual thoroughly and retain it for future reference.

Some features are:

Wireless system that allows you to listen to a program free 

from the restriction of a cord

Easy connection to TV and Hi-Fi Audio system component

Fast recharging function with secure charging mechanism

Noise reduction system to reproduce a clear sound with 

minimum transmission noise

Automatic tuning on headphones for optimum signal 

reception

3 transmission channels available

Up to 45 meters (150 feet) reception range*

Long playback time (approx. 25 hours)

High fidelity sound reproduction

Volume control function on the headphones

*  Transmission distance varies depending on conditions of use.

Modulation 

FM stereo

Carrier frequency  915.5 MHz, 916.0 MHz, 916.5 MHz
Channel 

Ch1, Ch2, Ch3

Transmission distance
 

Approx. 45 m (150 ft) of longest

Audio inputs 

Pin jacks (left/right)  

Stereo mini jack

Power requirements 

DC 12 V (from the supplied AC adaptor)

Dimensions 

Approx. 120 mm × 264 mm × 120 mm  

(4 

3

/

4

 × 10 

1

/

2

 × 4 

3

/

4

 in) (w/h/d)

Mass 

Approx. 470 g (1 lb 0.58 oz)

Rated power consumption
 

3.0 W

Operating temperature
 

5°C to 35°C (41°F to 95°F)

Frequency response
 

10 Hz – 22,000 Hz

Power source 

Built-in lithium-ion rechargeable battery

Mass 

Approx. 320 g (11.29 oz)

Operating temperature
 

5°C to 35°C (41°F to 95°F)

RF stereo transmitter TMR-RF985R

Wireless stereo headphones MDR-RF985R

AC adaptor (12 V) (1)

Connecting cable (stereo mini plug  pin plug × 2), 1 m (39 

3

/

8

 

in) (1)

Card warranty (1)

Operating Instructions (this manual) (1)

Design and specifications are subject to change without notice.

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To AC 

outlet

(Red)

(Off)

Complete when indicator 

turns off.

Connect the A/V component, following hookup  or  below.
 Using the headphone jack of the A/V component

L (white)

R (red)

Stereo mini plug

Headphone jack 

(Stereo mini jack)

TV, Digital music player, etc.

L (white)

R (red)

Stereo mini plug

Audio out  

(L/R) jacks

Stereo system, Blu-ray Disc player, DVD player, TV*, etc.

* In case of no headphone jack.

First change the radio frequency with the CHANNEL selector switch on the transmitter, 

then briefly press the AUTO TUNING button on the headphones.

The transmitter compresses the audio signal and converts it to RF signal. The headphones convert 

the received RF signal to an audio signal and decompresses it. This process reduces noise picked 

up during transmission.

 

 The transmitter compresses the audio signals dynamic range, then converts it to RF signal.
 Noise may occur due to long distance transmission, etc.
 The headphones convert the RF signal to an audio signal.
 Noise may occur during conversion.
 Decompression of the audio signals dynamic range reduces the noise level and improves the 

S/N (signal-to-noise) ratio.

Turn off the power of the headphones.

The transmitter starts sending RF signals automatically 

when it detects an audio signal from the connected 

component. Note that;

Noise may occur depending on the transmitter 

position and room conditions. It is recommended to 

place the transmitter in a location that produces the 

clearest sound.

If the transmitter is placed on a metallic table, you may 

hear noise, or the reception range may decrease. Do 

not place on a metallic table.

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When no signal is input for about 4 minutes, the 

transmitter turns off automatically*. The POWER 

indicator of the transmitter blinks for 60 seconds, then 

turns off. The transmitter restarts after receiving an audio 

signal again.

The transmitter may also turn off if low signal is input for 

about 4 minutes. In this case, raise the volume of the 

connected A/V component within the range where the 

sound is not distorted, then lower the volume of the 

headphones.

*  If signal noise is output from the connected A/V 

component, the transmitter may not turn off, even 

when no audio signal is input.

To reduce the risk of hearing damage, first lower the volume.

Tactile dot

Up

Down

Tactile dot

 Using the audio out (L/R) jacks of the A/V component

If you want to receive audio on the headphones while at the same time hearing audio from the television speakers: 

connect the transmitter to your Cable Box/Satellite Box rather than your television.

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6

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Wireless Stereo
Headphone System

©2012 Sony Corporation   Printed in China

4-429-926-12(1)

MDR-RF985RK

Operating Instructions

Mode d’emploi