I have a Behringer Xenyx QX1202X mixer and wanted to have a monitor attached. So I bought a single M-Audio BX5 active monitor speaker as I only need to monitor in mono. I have connected the 2 Main Out connections to the monitor speaker using a cable
Sweex XLR Male to 2 x Phono RCA Plug Stereo Audio Patch Cable Adapter Lead

The problem is that the monitor outputs a weird sound unless I pan the mixer inputs one way or another - when using the USB to provide the input then obviously I cant do that. Can I alter the wiring on the XLR male plug to provide a mono signal to the active speaker - if so - how? Thanks in advance

2 Answers 2


The tips (signal) of both RCA connectors need to land on pin 2 (hot) of the XLR connector, which would give you a rigged (but would work) passive summer. Sounds like that's not how that cable is wired. Based on your description, I'm guessing one of the RCA connectors is going to pin 2 and the other to pin three, which would give you the behavior you saw.

  • Thank you for your response
    – Dekko
    Commented Dec 31, 2021 at 11:55
  • RCA 1 Sig -> 10k (R1) -> XLR pin 2
  • RCA 2 Sig -> 10k (R2) -> XLR pin 2
  • RCA 1 GND -> XLR pin 1
  • RCA 2 GND -> XLR pin 1
  • XLR pin 3 -> XLR pin 1

This implements a passive summing mix of both RCA signals across an unbalanced connection on an XLR

  • Thank you. I cant get the XLR plug off the cable so I have ordered a new plug and will wire it as you suggest. Many thanks for your detailed answer
    – Dekko
    Commented Dec 30, 2021 at 23:49

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