My problem is a strange one. I have a computer connected to front and back speakers via 3.5mm audio jacks. Sometimes I use the computer with the monitor at my desk. Other times I'm using it to watch movies on a projector on the opposite side of the room.

Depending on whether I'm looking at the monitor or viewing the projector, the front and back speakers need to be switched, but it appears Windows does not provide an easy solution for such a simple task.

What I'm looking into doing is creating a box with two 3.5mm inputs, two 3.5mm outputs, and a switch on top that reverses the audio signal. This should be a simple task, but how can I construct this while insuring that I don't introduce a noticeable amount of static noise into the equation? Also how would I organize this on a breadbord?

Thanks for any input.

  • \$\begingroup\$ This question on SuperUser has some ideas. Remember that you also need to switch left and right: The rear right speaker becomes the front left speaker when you turn around. \$\endgroup\$
    – Ben Miller
    Commented Jun 15, 2015 at 17:21
  • \$\begingroup\$ @BenMiller The surround sound speakers are already mirrored in software, no? \$\endgroup\$
    – Samuel
    Commented Jun 15, 2015 at 18:40
  • 1
    \$\begingroup\$ Either way it shouldn't be hard to swap them if I need to. Simple trial and error. \$\endgroup\$ Commented Jun 15, 2015 at 22:21

1 Answer 1


How about something like this?


simulate this circuit – Schematic created using CircuitLab

Tie all the grounds together and flipping both switches will swap the speakers. The switches are DPDT. Keep all the wires short and you shouldn't introduce too much noise. You could do it all with one switch if you use a 4PDT, like this one.

Note that the Left Right channels are not flipped by this switch, that's already done in software if your computer is expecting the speakers to be behind the person, like it is for surround sound channels.

  • \$\begingroup\$ That is very helpful. Thank you! I was having a difficult time imagining this schematic. \$\endgroup\$ Commented Jun 15, 2015 at 18:39

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