Onkyo Error Code NG LR — Speaker Channel Fix

"NG: L R" appears during Onkyo's automatic speaker setup (AccuEQ) and means the receiver's calibration couldn't properly detect the front left and right speakers — it played a test tone and didn't get a clean result back. It's almost always a wiring or microphone issue, not a faulty receiver. Work the connections and the mic, and it clears.

Fix it

1. Check the front L/R speaker wiring. At the receiver and the speakers, make sure each wire is in the right terminal, + to + and − to − (matching colors), with no stray strands shorting across. A loose, reversed, or shorting connection is the #1 cause of NG. Re-strip and re-seat each; banana plugs make this reliable.
2. Confirm they're on the right channel. The front speakers must be in the Front L and Front R terminals, not a surround or zone-2 pair. Swapping them to the wrong posts produces NG.
3. Set up the calibration mic correctly. Plug the AccuEQ/calibration mic fully into the SETUP MIC jack, place it at ear height at the main seat, pointing up, and run the setup in a quiet room. A half-inserted mic, a noisy room, or a mic too far from the speakers all cause NG.
4. Raise the volume / check the speakers play. Before re-running calibration, confirm the front speakers actually make sound (play a stereo source). A blown speaker or a dead amp channel reads as NG. If one side is silent, fix that first.
5. Check impedance and re-run. Make sure the speakers match the receiver's rating (set the low-impedance mode if you're using 4Ω speakers), then re-run AccuEQ.

If NG persists on known-good speakers

• Power-cycle the receiver (unplug at least 30 seconds) and try again — a hung setup state can cause spurious NG.
• Try a different mic if you have one; calibration mics do fail.
• Test the channel manually: in the speaker setup menu, send a manual test tone to Front L and Front R individually. If one channel is silent with good wiring and a working speaker, that amp channel may have failed — a service issue.

FAQ

What does NG: L R mean on an Onkyo? During auto speaker setup, the receiver couldn't detect the front left/right speakers. Usually a wiring or mic problem, not a broken receiver. For other codes, see the full Onkyo receiver error code list.

My speakers are wired right but still NG. Check the calibration mic is fully plugged in, at ear height pointing up, in a quiet room. Then confirm the front speakers actually play a stereo source.

Could it be a short? Yes — a stray strand bridging the front terminals causes NG (and can trip protection). Re-strip the wires and make sure nothing shorts; banana plugs prevent it. If the receiver actually blinks and shuts off, that's Onkyo protection mode from a speaker short, not a calibration result.

It's NG on one side only. Swap that speaker's wire with the other side. If the problem follows the speaker, it's the speaker/cable; if it stays on the same terminal, that amp channel may have failed.