Sony MDR-RF940RK
Problem
No sound/
Muffled sound
Muffled sound
Distortion
Loud
background
noise
background
noise
Solution
Turn on the transmitter
first, then put on the
headphones.
first, then put on the
headphones.
Check the connection of the
audio/video equipment or
the AC power adaptor.
audio/video equipment or
the AC power adaptor.
Check that the audio/video
equipment is turned on.
equipment is turned on.
Turn up the volume on the
connected audio/video
equipment, if the
transmitter is connected to
the headphones jack.
connected audio/video
equipment, if the
transmitter is connected to
the headphones jack.
The mute function is
activated.
Use the headphones near
the transmitter.
activated.
Use the headphones near
the transmitter.
Charge the NC-AA (HJ)
batteries or replace both
batteries of the headphones.
batteries or replace both
batteries of the headphones.
If the transmitter is
connected␣ to␣ the␣ headphones
jack, turn down the volume
of the connected audio/
video equipment.
connected␣ to␣ the␣ headphones
jack, turn down the volume
of the connected audio/
video equipment.
Charge the NC-AA (HJ)
batteries or replace both
batteries of the headphones.
batteries or replace both
batteries of the headphones.
Move closer to the
transmitter. As you move
away from the transmitter,
more noise is likely to be
heard.
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.
connected to the
headphones jack, turn up
the volume of the connected
audio/video equipment.
Charge the NC-AA (HJ)
batteries or replace both
batteries of the headphones.
batteries or replace both
batteries of the headphones.
Troubleshooting
( Operating the system
Listening to a
program
1
Select the radio frequency with the
CHANNEL selector switch.
Select the same channel on the
headphones and the transmitter.
CHANNEL selector switch.
Select the same channel on the
headphones and the transmitter.
CH2
CH1
2
Turn on the audio/video equipment
then the transmitter.
then the transmitter.
POWER
3
Put on the headphones and the
power turns on automatically.
power turns on automatically.
4
Adjust the volume.
Note
If the transmitter is connected to the headphones
If the transmitter is connected to the headphones
jack of the source equipment, set the volume of
that equipment as high as possible without
distorting the audio signal.
that equipment as high as possible without
distorting the audio signal.
Auto power on/off function
When you remove the headphones, the
When you remove the headphones, the
power turns off automatically. Do not
apply pressure to the left ear pad when
not using the headphones, otherwise the
headphones will be switched on.
apply pressure to the left ear pad when
not using the headphones, otherwise the
headphones will be switched on.
/
Mute function
If a hissing noise is heard when the
If a hissing noise is heard when the
headphones are used outside of the
effective range (see the next section), the
mute function will be activated and the
sound will not be heard from the
headphones. To restore the sound,
move near toward the transmitter.
effective range (see the next section), the
mute function will be activated and the
sound will not be heard from the
headphones. To restore the sound,
move near toward the transmitter.
When no audio signal is received for
more than approximately five
minutes
minutes
The transmitter will be burned off
automatically.
After listening to a program
Take the headphones off before turning
Take the headphones off before turning
off the transmitter. If you turn off the
transmitter first, you may hear some
noise.
transmitter first, you may hear some
noise.
The effective areas
of the transmitter
of the transmitter
The optimum distance is up to
approximately 130 feet (40m) without
the system picking up some interference.
However, the distance may vary
according to the surroundings and
environment. If the system picks up
some noise while using it within the
above mentioned distance, reduce the
distance between the transmitter unit
and the headphones, or select the other
channel.
approximately 130 feet (40m) without
the system picking up some interference.
However, the distance may vary
according to the surroundings and
environment. If the system picks up
some noise while using it within the
above mentioned distance, reduce the
distance between the transmitter unit
and the headphones, or select the other
channel.
Notes
• When you use the headphones inside the
• When you use the headphones inside the
effective areas of the transmitter, the transmitter
can be placed in any direction from the listener.
can be placed in any direction from the listener.
• Even within the signal reception area, there are
some spots (dead point) where the RF signal can
not be received. This characteristics is inherent to
RF signals, and does not indicate malfunction.
By slightly moving the transmitter, location of
the dead point can be changed.
not be received. This characteristics is inherent to
RF signals, and does not indicate malfunction.
By slightly moving the transmitter, location of
the dead point can be changed.
Replacing the ear
pads
pads
When the ear pads become dirty or
damaged, you can get replacements
from your Sony dealer. Replace them as
illustrated below.
damaged, you can get replacements
from your Sony dealer. Replace them as
illustrated below.
1
Remove the old ear pad by pulling it
out of the groove on the housing.
out of the groove on the housing.
2
Place the new ear pad on the
housing and insert the edge of the
pad into the groove as illustrated.
housing and insert the edge of the
pad into the groove as illustrated.
Make sure that the entire edge of the ear
pad is securely inserted into the groove.
pad is securely inserted into the groove.
( Additional information
Precautions
• When the headphones are not to be
used for a long period of time, remove
the dry batteries (if any) to avoid
damage caused by battery leakage and
subsequent corrosion.
the dry batteries (if any) to avoid
damage caused by battery leakage and
subsequent corrosion.
• When the transmitter is not to be used
for a long period of time, disconnect
the AC power adaptor from the AC
outlet holding the plug. Do not pull
on the cord.
Also remove the batteries to avoid
damage caused by battery leakage and
subsequent corrosion.
the AC power adaptor from the AC
outlet holding the plug. Do not pull
on the cord.
Also remove the batteries to avoid
damage caused by battery leakage and
subsequent corrosion.
• Do not leave the wireless stereo
headphone system in a location subject
to direct sunlight, heat or moisture.
to direct sunlight, heat or moisture.
Notes on headphones
Preventing hearing damage
Avoid using headphones at high
Preventing 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.
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.
Keep the volume at a moderate level.
This will allow you to hear outside
sounds and to be considerate to the
people around you.
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
the nearest Sony dealer.
covered in this manual, please consult
the nearest Sony dealer.
Be sure to bring the headphones and the
transmitter to the Sony dealer when
requiring repair work.
requiring repair work.
Specifications
General
Carrier frequency
000 – 000 MHz
Channel
Ch1, Ch2
Modulation
FM stereo
Frequency response
20 – 20,000 Hz
Transmitter
RF Power
Less than 94 dBµV/m at 3 m
Power source
DC 4.5 V: supplied AC power
adaptor
adaptor
Audio input
stereo mini plug
Dimensions
Approx. 90 mm dia x 35 mm
(3
5
/
8
x 1
7
/
16
in.) (w/h)
Mass
Approx. 200 g (7.1 oz.)
incl.batteries
incl.batteries
Headphones
Power source
DC 3 V: 2 x R6 (size AA) battery
Mass
Approx. 270 g (9.5 oz.) incl.
batteries
batteries
Optional accessories
Plug adaptor PC-236HG
(stereo mini jack ˜ monaural mini plug)
(stereo mini jack ˜ monaural mini plug)
Design and specifications are subject to change
without notice.
without notice.