Sony MDR DS4000 - Manual (Page 21)

Operation
21 GB
Enjoying with Additional Headphones
In this system, by using additional MDR-IF4000 cordless infrared headphones (sold
separately), more than one person can enjoy the surround sound experience
wirelessly at the same time.
Charge additional headphones with the processor of this system.
* There is no limit to the number of headphones that can be used within the infrared
transmission area.
Notes
• The processor turns off automatically while charging. Remove these headphones from the
processor when using other headphones.
• Because this unit employs a digital infrared transmission system, cordless infrared analogue
headphones (MDR-IF3000, etc.) cannot be used.
• This unit is not compatible with the MDR-DS8000 since the infrared transmission method is
different. The MDR-IF8000 cannot be used.
Processor
MDR-IF4000 (sold separately)