Simple passive audio summing


Joined Aug 21, 2008
Assuming that you are talking about the audio input to an amplifier:
Connect one 1k resistor to the right channel. Connect one 1k resistor to the left channel. Connect the other end of both resistors together and that is the mono output. All shields (grounds) are connected together.

Or do you want to connect the outputs of two amplifiers to drive one speaker? (I don't know how to do that safely, but I'll bet somebody does).
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Thread Starter


Joined Apr 10, 2008
Yes i am looking to keep it balanced. Could i just do this twice (i.e. sum the hot pins together then the cold)?

What i want to do is more for mixing purposes than for an amplifier... simply, i want a button that i'll press that will sum a signal to mono. Sorry, shoulda been more clear.