I have a pair of Sennheiser PC360 headphones that I use with an amp to listen to music, movies, etc daily. My 50lb pitbull loves to get his legs caught in the cable and yank the headphones off my head. Today the headphones decided they'd been thrown across the room one too many times and didn't sound right anymore. The sound they produce sounds distant and echo-y, almost as if I have a cheap mixer effect for a concert hall turned on or something.

I discovered if I half-pull out the headphone plug from the jack, the volume and quality of sound return to normal but the output appears to be mono, which makes sense since I'm misaligning the connections on the plug.

I thought maybe the ground wire had come loose in the plug so I went ahead and cut it off and proceeded to wire in a new jack to the cord. Still has the exact same issue as when I started.

I just used an online audio tester which lets you play a Left channel, Right channel, and combined Left/Right channel sound clip... when I play Left-only or Right-only, the quality and volume sound fine. However when I play the Left/Right combined (center) channel, its almost as if the channels cancel each other out. It's quiet, distant. empty sound. Listening to music, sometimes the higher vocal frequencies don't come through at all. Bass is nonexistent.

Obviously this is a wiring issue since the headphones themselves sound fine when I pull the plug halfway out, what could be the issue?

1 Answer 1


Your ground connection is missing from the headphones. Check the continuity from each ear-piece to the ground connection which is the Sleeve on your 3-pin stereo plug. You should be able to do this with any cheap multimeter. The reason you can still hear stuff is because there is a link between the grounds at the earpiece level, just not between the earpieces and the connector.

  • Thanks for your response Mark. When you say "from each ear piece", do you mean I need to get the headphones apart to test both ends of the cable? As I mentioned in the post I checked the wiring myself already at the plug-end and the ground is fine - maybe it came loose on the ear piece end?
    – Andrew
    Commented Dec 21, 2016 at 9:26
  • yeah that is what I am thinking. What you are hearing at the moment is the "difference" signal - basically you're listening to Left minus Right which is why there is no bass and it sounds phasy and tinny. It could also be that there is a break in the cable. If "spot" has been playing with it and getting the cable wrapped around various things and chewing on it, there could well be a case for a replacement cable.
    – Mark
    Commented Dec 21, 2016 at 9:27
  • Also try and test the continuity across the L/G and R/G connections at the connector end. You should see roughly 8 ohms resistance there. If there is no continuity whatsoever then that indicates an issue. (Tip/Sleeve and Ring/Sleeve)
    – Mark
    Commented Dec 21, 2016 at 9:30
  • Thanks, I'll take them apart tomorrow and find my multimeter.
    – Andrew
    Commented Dec 21, 2016 at 9:34

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