Sony MDR-RF4000K Specification Guide

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MDR-RF4000K
Wireless digital RF headphones
Differences in details  
40mm drivers deliver deeper bass, lower distortion and wider dynamic range.
Stay comfortable as long as you listen
A wide, self-adjusting headband distributes the headphone's weight over a wide area, reducing pressure and 
improving comfort. 
Listen from a distance
Radio Frequency (RF) transmission sends signals from the transmitter to the headphones, allowing high fidelity 
sound reproduction. You can enjoy the accompanying reception range – up to 100 feet – even when you move 
outside the line of sight of the transmission. 
Battery life for extended viewing
The supplied rechargeable NiMH battery lets you enjoy up to eight hours of continuous on a single charge
1
. The 
slim, folding design fits snugly into the charger (included). Substituting a single AAA battery for the rechargeable 
NiMH pack provides 10 hours of power. 
Specifications
Audio
Distortion
1% or less (1 kHz)
Driver Unit
40 mm
Effective Range
Approximately 100 feet (30 m)
Frequency Response
10 - 22,000Hz 
Transmitter
2.404 GHz - 2.476 GHz, GFSK
Tuning
Auto Tuningon headphones
Volume Control
Yes (Rotary)
General
Design
Over-the-head, Home-Surround Sound
Diaphragm
PET
Headband
Wide, Self-Adjusting
Magnet
Neomydium
Power On/Off
Power turns ON when headphones are worn; Red LED illuminates
Type of Use
Home
Hardware
Communication
Wireless Digital 2.4GHz Radio Frequency
Headphone Type
Closed, Dynamic
Inputs and Outputs
Audio In
Analog Phono Input (left/right), Analog Stereo Input mini jack (x1) 
Power
Battery Charging (Approx)
15 hours
Battery Indicator
Power-on LED indicator
Battery Life (Approx)
8 hours