Question Left and right channel imbalance when connected to receiver via "Main" or headphone jack but "Zone 2" channel balance sounds fine.


May 28, 2011
I'm inexperienced with audio tech so I'll try my best explaining this.

I have a used Anthem MRX500 receiver that has audio imbalance in the "Main" port and the headphone jack. The "Main" port and the headphone jack output much louder volume to the left speaker while the right is significantly quieter.

For reference I'm using a 2 channel setup with bookshelf speakers connected via optical cables. The settings have been reset to factory defaults several times as well so left over settings wouldn't be the cause.

When hooked up to "Main" on my receiver, with the left speaker connected to "Front L" and right speaker in "Front R" the left speaker is louder. If I swap these inputs and have the left speaker in "Front R" and the right speaker in "Front L" the right speaker will be louder. So essentially, whichever speaker is connected to "Front L" will be louder while whichever one is connected to "Front R" will be quieter.

If I plug headphones into the headphone jack it has same issue where left is louder and right is much quieter.

If I instead connect my speakers to "Zone 2" the audio appears to sound properly balanced between the 2 speakers.

  1. What could be causing this?
  2. Is there something defective with the receiver? I'm not sure how old my specific model is, but the MRX500 appears to have released 9 or 10 years ago. Could age/ Wear and tear be the culprit or some part failing?
  3. Would it be worth taking in for repair or am I better off just using Zone 2 for now until upgrading with a replacement receiver?


Mar 28, 2010

When I first read the question my first thought was the settings were probably wrong, but since you've reset them...perhaps it's a hardware problem at this point. If I were to hazard a guess, I think you have problem in the pre-amp stage, afaik usually the headphone jack in most AVR's will use the same pre-amp output as the mains use which is why it's a problem for headphones too, and since each channel has it's own pre-amp, it's why zone 2 is unaffected. I don't have a suggestion to fix the problem (other than trying to manually balancing then within the settings) but I can suggest a couple of things for you:

First would be to contact Anthem directly with your problem. They are small enough where, at least up to 2-3 years ago, they were good with customer support and the should give you an idea for a course of action.

Secondly, you can go over to and ask in the receiver, amp, and processor main thread for help as there are some very knowledgeable people there.

To be honest, probably both places with simply say to go with your suggestion to use zone 2 until you want/need to get a new avr. But, maybe there's a somewhat easy and inexpensive fix to the problem.