welcome to store.sony.com. we apologize but this site is not yet accessible for our visually impaired customers. in order to provide you the best possible service, please call one eight hundred two two two seven six six nine for assistance.

2.4GHz Digital RF Wireless Headphones

Model number: MDR-RF4000K
Rated 4 out of 5 stars
Serious sound, no wires. These high-fidelity headphones deliver deep bass, a wide sound range and a cushy fit.

ADDITIONAL IMAGES:

$169.99

Earn 170 Sony Rewards points on this purchase.

Unplug and enjoy. The MDR-RF4000K digital wireless headphones system gives you the freedom to travel up to 100 feet from your sound source while delivering phenomenal sound. This system includes Ni-MH rechargeable batteries, 2.4GHz RF digital transmission and headphones with a 40mm driver for deep bass. Includes charger and ultra-long battery life.

Differences in details

40mm drivers deliver deeper bass, lower distortion and wider dynamic range.

Battery life for extended viewing

The supplied rechargeable NiMH battery lets you enjoy up to eight hours of continuous on a single charge1. 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.

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.

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.

Product Specifications

Hardware

  • Communication : Wireless Digital 2.4GHz Radio Frequency
  • Headphone Type : Closed, Dynamic

Weights and Measurements

  • Cord Length (Approx.) : 39 3/8 in. (1.0 m) Stereo connecting cable
  • Dimensions (Approx.) : Transmitter: 9 1/4 x 3 x 4 3/4 in. (246 x 75 x 120 mm)
  • Weight (Approx.) : Approximately 15.2 oz. (430 grams) Including suppliied battery

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 Tuning on headphones
  • Volume Control : Yes (Rotary)

Inputs and Outputs

  • Audio In : Analog Phono Input (left/right), Analog Stereo Input mini jack (x1)

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

Power

  • Battery Charging (Approx) : 15 hours
  • Battery Indicator : Power-on LED indicator
  • Battery Life (Approx) : 8 hours
  • Battery Type : AAA Ni-MH x 2
  • Input Power : AC Power Adaptor (5.2V, 800mA)
  • Input Voltage : DC 5.2 V (from supplied AC power adaptor)
  • Power Requirements : Rechargeable nickel-metal hydride battery (supplied) or commercially available (size AAA) alkaline batteries

In the Box

  • BP-HP550-11 (550 mAh) (1)
  • Stand (1)
  • AC power adaptor (5.2 V) (1)
  • Connecting cable (stereo mini plug - pin plug × 2), 1 m (39 3/8 in) (1)
  • Card warranty (1)
  • Rechargeable nickel-metal hydride battery
  • Unimatch plug adaptor (stereo mini jack - stereo phone plug) (1)
  • Operating Instructions (this manual) (1)

Product Profile

Support

Product Warranty

MDR-RF4000K 4 5 2 2
POOR BATTERY This high price headphone uses same battery as RF925. Battery becomes useless in under a year. Replacement battery cost $25. Web site says can substitute battery pack with one AAA battery. Pack is two cel and takes two AAA batteries to replace pack. Bought this to go with new TV. Have had several 925s. Thought an upgrade would solve the battery problem. Guess not. December 2, 2011
Excellent Purchase All around excellent product. Ease of setup & installation is a breeze. My Mother had to use closed captioning to watch her TV (as she is very hearing impaired) until I set these up for her. Ever since she has raved about them. She says its so nice not too have to read the TV. I highly recomend this product. One of the best purchases I ever made. They are a little expensive but, well worth the price. I'd give them 10 stars but, they only allow 5 'lol' March 9, 2011
1-2 of 2

VIEW FOOTNOTES


1. Actual battery life may vary based on product settings, usage patterns and environmental conditions.

© 2010 Sony Electronics Inc. All rights reserved. Reproduction in whole or in part without written permission is prohibited. Sony is a trademark of Sony. Features and specifications are subject to change without notice. Non-metric weights and measures are approximate and may vary.

Sorry, the (model number) is no longer available.

Interested in something new?

Explore the latest models now.

Shop Now