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5 Rest the headphones on the transmitter so
that the transmitter’s POWER/CHARGE
indicator lights in red.
Please place the headphones on the transmitter so that
the triangle arrow would be matched. If the headphones
are not properly placed, it will not be charged.
Charging will take about 16 hours, after which the
POWER/CHARGE indicator will go off.
About the charging method of the system
This system employs a contactless charge method that
requires no terminals by the electromagnetic induction.
Notes
•
Do not leave any metallic objects (coin, clip, etc.) near
the transmitter’s charging point. The transmitter and
the metal might become hot and it is dangerous.
•Do not leave any objects susceptible to magnetism
(cash cards, floppy disks with magnetic coding, etc.)
near the system. Exposure to the transmitter’s
electromagnetic field may render them unusable.
•
Do not place a radio near the system. A noise may be heard
from the radio. In such a case, change the angle of the radio
or move away from the system so that a noise is not heard.
When the transmitter’s POWER/CHARGE
indicator does not light up red
Check if the right and left headphones are rested on
the transmitter correctly. Remove the headphones and
replace them on the transmitter again so that the
POWER/CHARGE indicator lights in red.
To recharge the headphone battery after use
Place the headphones on the transmitter after use.
Since the built-in timer recognizes when charging is
complete, there is no need to remove the headphones
from the transmitter after charging.
Notes
• About 16 hours after the beginning of every battery
charge, the charging ends and the transmitter’s
POWER/CHARGE indicator lights off, regardless of
the battery level. This is the automatic control by the
timer in the transmitter.
• Even after repeated charge, the battery is durable
for use, because the unit is designed with the low
electrical current system for charging the battery.
• The transmitter automatically stops sending RF
signals while charging the battery.
• This system is designed to charge only the supplied
rechargeable battery type BP-HP550-11 for safety.
Note that other types of rechargeable batteries
cannot be charged with this system.
• If dry batteries are installed, they cannot be charged.
• Do not attempt to use the supplied BP-HP550-11
rechargeable battery for other components. They are
for use with this system only.
• Charge in an environmental temperature of
between 0 °C and 40 °C (between 32 °F and 104 °F).
Charging and usage hours
Approx. charging Approx. usage time*
1
hours*
1
1 hour 60 minutes*
3
40 minutes*
3
16 hours*
2
18 hours*
3
14 hours*
3
*
1
at 1 kHz, 1 mW+1 mW output
*
2
hours required to fully charge an empty battery
*
3
Time stated above may vary, depending on the
temperature or conditions of use.
Using the headphones with dry batteries
(sold separately)
Commercially available (size AAA) dry batteries can also
be used to power the headphones. Install the batteries in
the same manner as described in steps 1 through 3 of
“Charging the supplied rechargeable battery.”
When dry batteries are installed, the battery charge
function will not be activated.
Battery life
(Using Sony alkaline batteries LR03/AM-4 (N))
Model Approx. hours*
1
MDR-RF925RK 28 hours*
2
MDR-RF970RK 22 hours*
2
*
1
at 1 kHz, 1 mW+1 mW output
*
2
Time stated above may vary, depending on the
temperature or conditions of use.
Wireless Stereo
Headphone System
© 2007 Sony Corporation Printed in China
Operating Instructions
Mode d’emploi
3-100-340-12(1)
English
WARNING
To reduce the risk of fire or electric shock,
do not expose this apparatus to rain or
moisture.
To reduce the risk of fire or electric shock, do not place
objects filled with liquids, such as vases, on the
apparatus.
To avoid electrical shock, do not open the cabinet.
Refer servicing to qualified personnel only.
Connect AC power adaptor to an easily accessible AC
outlet. Should you notice an abnormality in AC power
adaptor, disconnect it from the AC outlet
immediately.
Do not install the appliance in a confined space, such
as a bookcase or built-in cabinet.
Do not expose the battery to excessive heat such as
direct sunlight, fire or the like.
Information
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/
Declaration of Conformity
Trade Name: SONY
Model No.: MDR-RF925R
MDR-RF970R
(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.
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 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.
– 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.
For the customers in Canada
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.
For the customers in the USA and Canada
RECYCLING NICKEL METAL HYDRIDE
BATTERIES
Nickel Metal Hydride
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 Nickel Metal
Hydride batteries.
Welcome!
Thank you for purchasing the Sony MDR-RF925RK/
RF970RK Wireless Stereo Headphone System. Before
operating the unit, please read this manual thoroughly
and retain it for future reference.
Some features are:
•Wireless transmission lets you enjoy TV or music
without the restriction of a cord
•High fidelity sound reproduction
•Enhanced clarity of sound with minimal
transmission noise by use of noise reduction
technology (MDR-RF970RK only)
•Easy connection to TV and Audio system equipment
•Up to 150 feet reception range
•Hassle-free recharging by simply placing
headphones on the transmitter base station;
headphones charge via electromagnetic induction
•Convenient volume adjustment on the headphones
•Comfortable fit with adjustable headband and
complete coverage of the ear
•Headphones automatically turn on when placed
over the head and turn off when removed, saving
battery power
Notes on receiving
performance
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.
N Getting started
Unpacking
Check that you have the following items:
•The headphones (1)
•The transmitter (1)
•AC power adaptor (1)
•Connecting cord (1) (phono plugs y stereo
miniplug), 1 m
• Unimatch plug adaptor (1) (stereo mini jack y
stereo phone plug) (MDR-RF970RK only)
• Rechargeable nickel-metal hydride battery
BP-HP550-11 (1)
Charging the supplied
rechargeable battery
The supplied rechargeable nickel-metal hydride battery
is not charged from the first time you use it. Be sure to
charge it before use.
To charge the headphones, place them on the transmitter.
1 Press the PUSH button of the left housing to
open the battery compartment lid.
The battery compartment lid comes off.
L
2 Insert the supplied rechargeable nickel-
metal hydride battery into the battery
compartment matching the 3 terminal on
the battery to the 3 mark in the
compartment.
Do not use rechargeable battery other than the
supplied one.
3 Close the battery compartment lid.
1Insert the tab into the hole at the upper left.
2Close the lid until it clicks.
1
L
2
4 Connect the supplied AC power adaptor to
the transmitter.
Notes on Batteries
• Do not charge a dry battery.
• Do not carry a dry battery together with coins or
other metallic objects. It can generate heat if the
positive and negative terminals of the battery
accidentally come into contact with metallic objects.
• If you are not going to use the unit for a long time,
remove the batteries to avoid damage from battery
leakage or corrosion.
Checking the remaining battery power
Pull up the self-adjusting band and check the POWER
indicator located on the right housing. The battery is
still serviceable when the indicator lights in red.
Charge the rechargeable battery or install new dry
batteries if the POWER indicator light dims, flashes, or
the sound becomes distorted or noisy.
Note
The rechargeable nickel-metal hydride battery should
be replaced with new one when they last only half the
expected time after a proper recharging. The
rechargeable battery type BP-HP550-11 is not
commercially available. You can order the battery
from the store where you purchased this system, or at
your nearest Sony dealer.
Setting up the transmitter
1 Connect the transmitter to audio/video
equipment.
Select one of the hookups below depending on the
jack type:
A To connect to a headphones jack
B To connect to LINE OUT or REC OUT
* “WALKMAN” and “WALKMAN” logo are
registered trademarks of Sony Corporation.
Note
Refer to documentations of a connected component
for details about the specifications or the settings for
audio out jacks.
2 Connect the supplied AC power adaptor to
the transmitter.
Notes
•Use only the supplied AC power adaptor. Do not
use any other AC power adaptor.
•When the transmitter is placed on or near a TV, it
may pick up a noise. In such a case, place the
transmitter away from the TV.
•If the connected equipment has the AVLS
(Automatic Volume Limiter System) function, be
sure to turn the function off when using the
transmitter. Otherwise, you will have to turn up the
volume of the headphones, and that may cause
noise.
N Operating the system
Listening to a program
Before listening
To reduce the risk of hearing damage, first lower the
volume.
1 Turn on the audio/video equipment
connected to the transmitter.
If the transmitter is connected to the headphone
jack, set the volume control of the audio source
equipment as high as possible but not so high that
the audio signal becomes distorted.
2 Remove the headphones from the
transmitter.
The transmitter’s POWER/CHARGE indicator
lights up green.
3 Select the radio frequency with the
CHANNEL selector switch.
12
CHANNEL
3
4 Put on the headphones.
When you put on the headphones, the
headphone’s power turns on automatically.
The POWER indicator on the right housing glows
red.
Be sure to put the right housing R on your right
ear and the left housing L on your left ear.
Wear the headphones vertically on your head so
that auto power on function is properly activated.
5 Set the channel to that of the transmitter
with the selector (or button) on the right
housing of the headphones.
A MDR-RF925RK
Select the channel to that of the transmitter with
the TUNING selector on the right housing of the
headphones.
When tuning has completed, turn up the volume
to a moderate level with the VOLUME control on
the right housing.
R
231
VOLUME
B MDR-RF970RK
Press the TUNING button briefly for automatic
tuning of the headphones. If you do not receive a
clear audio signal, press it again.
When tuning has completed, turn up the volume
to a moderate level with the VOLUME control on
the right housing.
R
TUNING
VOLUME
Sending RF signals from the transmitter
The transmitter starts sending RF signals automatically when
it detects an audio signal from the connected equipment.
If it does not detect an audio signal for more than about 10
minutes, the transmitter will stop sending RF signals, and the
POWER/
CHARGE
indicator will turn off.
When the transmitter receives an audio signal again, it starts
sending the RF signals, and the POWER/
CHARGE
indicator will light up green again.
If the audio signal is very weak, the transmitter does not
send RF signals. If the transmitter is connected to a
headphone jack, make sure the volume of the equipment
connected is set to 5 - 6 or higher.
You may not hear the beginning of the sound from the
headphones until the transmitter starts sending the RF
signals after detecting an audio signal.
The headphones automatically turn off
when they are taken off
– Auto power on/off function
Do not pull up the self-adjusting band when not in
use, as this will consume the battery power.
Notes
•If hiss is heard, move closer to the transmitter.
•You may hear some noise when you disconnect the
AC power adaptor from the transmitter before turn
off the headphones.
Noise Reduction process (MDR-RF970RK
only)
The transmitter unit compresses the audio signal and
converts it to RF signal. The headphones unit converts
the received RF signal to an audio signal and
decompresses it.
This process reduces noise picked up during
transmission.
input signal
output signal
decompression
compression
dynamic range
Transmitter unit Headphones unit
RF transmission
noise level (low)
1
2 34
5
1 The transmitter unit compresses the audio signals
dynamic range, then converts it to RF signal.
2 Noise may occur due to long distance
transmission, etc.
3 The headphones unit converts the RF signal to an
audio signal.
4 Noise may occur during conversion.
5 Decompression of the audio signals dynamic range
reduces the noise level and improves the S/N
(signal-to-noise) ratio.
The effective areas of
the transmitter
The optimum distance is up to approximately 150 feet
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 unit and
the headphones, or select another channel.
Notes
•When you use the headphones inside the effective
areas 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 characteristics is inherent to RF
signals, and does not indicate malfunction. By
slightly moving the transmitter, location of the dead
spot can be changed.
Replacing the ear pads
The ear pads are replaceable. If the ear pads become
dirty or worn out, replace them as illustrated below.
The ear pad is not commercially available. You can
order replacements from the store where you
purchased this system, or at your nearest Sony dealer.
1 Remove the old ear pad by pulling it out of
the groove on the housing.
2 Place the new ear pad on the driver unit.
Hang the edge of the ear pad on one side of the
driver unit’s groove edge, then turn the edge of
ear pad around the driver unit as illustrated
below.
When the ear pad is securely inserted into the
groove, adjust the ear pad to the vertical position.
MDR-RF925RK
MDR-RF970RK
N Additional information
Precautions
•
If the transmitter is not to be used for a long period of
time, disconnect the AC power adaptor from the AC
outlet by holding the plug. Do not pull on the cord.
•Do not leave the wireless stereo headphone system
in a location subject to direct sunlight, heat or
moisture.
Notes on headphones
To reduce the risk of hearing damage
Avoid using headphones at high volume. Hearing
experts advise against continuous, loud and extended
play. If you experience a ringing in your ears, reduce
the volume or discontinue use.
Caring for others
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.
Troubleshooting
No sound/Muffled sound
, Check the connection of the audio/video
equipment or the AC power adaptor.
, Check that the audio/video equipment is
turned on.
, Turn up the volume on the connected audio/
video equipment, if the transmitter is
connected to the headphones jack.
, Change the radio frequency with the
CHANNEL selector switch on the transmitter,
then set to the same radio frequency with the
TUNING selector (or TUNING button) on the
right housing of the headphones.
, The muting function is activated.
•Use the headphones near the transmitter.
, The headphones’ POWER indicator light turns
off, dims, flashes, or sound becomes distorted
or noisy.
•Charge the rechargeable battery if it is weak,
or replace alkaline batteries with new ones. If
the POWER indicator is still off after charging
the battery, take the headphones to a Sony
dealer.
Distortion
, If the transmitter is connected to the
headphones jack, turn down the volume on the
connected audio/video equipment.
, Change the radio frequency with the
CHANNEL selector switch on the transmitter,
then set to the same radio frequency with the
TUNING selector (or TUNING button) on the
right housing of the headphones.
, The headphones’ POWER indicator light turns
off, dims, flashes, or sound becomes distorted
or noisy.
•Charge the rechargeable battery if it is weak,
or replace alkaline batteries with new ones. If
the POWER indicator is still off after charging
the battery, take the headphones to a Sony
dealer.
Loud background noise
, Move closer to the transmitter. As you move
away from the transmitter, more noise is likely
to be heard.
, If the transmitter is connected to the
headphones jack, turn up the volume of the
connected audio/video equipment.
, Change the radio frequency with the
CHANNEL selector switch on the transmitter,
then set to the same radio frequency with the
TUNING selector (or TUNING button) on the
right housing of the headphones.
, The headphones’ POWER indicator light turns
off, dims, flashes, or sound becomes distorted
or noisy.
•Charge the rechargeable battery if it is weak,
or replace alkaline batteries with new ones. If
the POWER indicator is still off after charging
the battery, take the headphones to a Sony
dealer.
Specifications
General
Carrier frequency
915.5 MHz, 916.0 MHz, 916.5 MHz
Channel Ch1, Ch2, Ch3
Modulation FM stereo
Frequency response
MDR-RF925R: 20 – 20,000 Hz
MDR-RF970R: 10 – 22,000 Hz
Transmitter TMR-RF925R, RF970R
Power source DC 12 V: supplied AC power adaptor
Audio input Phono jacks, stereo mini jack
Dimensions Approx. 216 × 105 × 96 mm
(8
5
/
8
× 4
1
/
4
× 3
7
/
8
in) (w/h/d)
Mass Approx. 220 g (7.77 oz)
Headphones MDR-RF925R, RF970R
Power source Supplied rechargeable nickel-metal
hydride battery BP-HP550-11 or
commercially available (size AAA) dry
batteries
Mass Approx. 300 g (10.59 oz) incl. Battery
Design and specifications are subject to change
without notice.
Charging point
MDR-RF925RK MDR-RF970RK
Polarity of the plug
VOLUME control
TUNING
selector
12
CHANNEL
DC IN 12V
RALINPUT
3
B
Transmitter
AC power adaptor
(supplied)
To an AC
outlet
To DC IN
12V jack
Transmitter
Headphones
Self-
adjusting
band
PUSH
button
Rechargeable
battery
LR
Transmitter
Lines of magnetic
force
Headphones
12
CHANNEL
DC IN 12V
RALINPUT
3
B
Transmitter
AC power adaptor
(supplied)
To an AC
outlet
To DC IN
12V jack
VOLUME control TUNING
button
LR
Transmitter
Headphones
POWER/CHARGE
indicator
12
CHANNEL
DC IN 12V
INPUT
3
BRAL
Transmitter
To INPUT A
jacks
Connecting cord
(supplied)
Unimatch plug
adaptor
(MDR-RF970RK:
supplied)
Right
channel (red)
Left channel
(white)
WALKMAN*,
TV, etc.
To headphones
jack (Stereo
mini jack)
To headphones
jack (Stereo
phone jack)
12
CHANNEL
DC IN 12V
INPUT
3
BRAL
Transmitter
To INPUT B
jack
Connecting cord
(supplied)
To LINE OUT or
REC OUT jacks
Right
channel (red)
Left channel
(white)
Stereo system,
VCR, etc.