Toshiba HR40X - 4 Channel Quadrophonic Headphones, 1973, made in Japan

 
Link: radiomuseum

You can switch it from 2 channel to 4 channel.

Covered in a mottled brown, leather type material.
Each ear plate houses have 2 speakers, which provide the balance sound, externally they are labelled left/right and front/rear.
Left plate houses the 2/4 channel switch. the cable has front/rear label too. Two plugs are all 6.3 mm phone connectors. The headphone has a adjustable headband and stop with two screws.

Country:  Japan
Manufacturer / Brand:  Toshiba Corporation; Tokyo
alternative name  
Shibaura Engineering Works
Brand Tokyo Shibaura
Year: 1973 ? Category: Loudspeaker, headphone or earphone
Wave bands - without
Details
Loudspeaker - Is a Headphone or Earphone
Power out
Model: HR40 - Toshiba Corporation; Tokyo
Material Various materials
Notes
  • Quadrophonic headphones.
  • 4 channel / 2 channel switcher.
  • Each 2 dynamic LS systems, 20-20000Hz, 4 x 1mW
  • Impedance 8 oHm