I have to transmit audio from point A to point B and all I have connecting those two points is a composite video cable (RGB).

(History. Old setup was: Computer->AVR[Video->Projector by composite, Audio->Speakers]. New setup: Chromecast->Projector(Video->Screen, Audio->Receiver by composite?)

Can audio be carried by the composite video cable?

  • 1
    yes, one channel per plug.
    – dandavis
    Commented Aug 3, 2018 at 6:24
  • No adapter necessary?
    – Wynne
    Commented Aug 3, 2018 at 11:31
  • 1
    RCA jacks are used on both component video cables and composite RWY A/V cables, so no adapter should be needed. As far as I can tell, the only difference between the typical RWY and the RGB cables is color codes.
    – Chris M.
    Commented Aug 3, 2018 at 11:39
  • 4
    I'm voting to close this question because it's about AV not home improvement
    – mmathis
    Commented Aug 3, 2018 at 14:49
  • you might need an adapter, depending on your input and output connectors. RCA is a common one for analog audio, as is a headphone jack. You can get headphone to stereo RCA adapters anywhere, even places like walgreens.
    – dandavis
    Commented Aug 3, 2018 at 15:31

1 Answer 1


If I understand what you're doing, you want to put the chromecast on the projector on the ceiling, and use two of the RGB to run the audio out back to the receiver.

Yes, it will work, I have done this many times to re-purpose cables installed in home theater and commercial AV. The RGB cables for component video (RGB) and composite video (yellow) are just 75 ohm impedance coaxial cables with RCA ends, same type typically used in red and white for stereo audio. The color coding only matters to the person plugging things in.

Per google support (https://support.google.com/chromecast/answer/6280276) you'll need a 3.5mm to RCA stereo adapter cable.

  • I agree the wire is the same, the plastic covers make it easy to know the cable connections at each end.
    – Ed Beal
    Commented Aug 4, 2018 at 16:00

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