Driver volume/frequency response is audibly off on the left. How to diagnose?

As the title states, my Beyer CS pair has an odd difference between left and right drivers (as confirmed by flipping them around. Problem follows driver).

I'm unsure if it's just a difference in midrange, or overall volume, but it does seem to be a midrange difference.

The louder driver is on the left where the detachable cable entry is, so my guess is that it's because of a shitty cable connecting the right driver. Or the actual jack socket being shit. Or something.

Does anyone have ideas as to how I can diagnose the issue, maybe even suggestions as to what the specific issue could be?

 

Smaller differences, sure, but this is a major "all voices sound panned towards the left" issue. No other cans have the issue. And if I push on the cable a little near the cup, the audio drops out. So I have reason to believe it's related to the wiring...

 

New? Warranty? Don't waste time: return them.

Not new? No warranty? Turn the balance control until the problem disappears and then forget it.

Be glad you have balanced ears!

 

If the jack was causing issues, the volume would be lower instead of higher.

 

It would be. If you look at it from the other side

 

If the jack has a bad contact on the right channel ring, that's the channel that would suffer though.

 

Alright guys, I confirmed the problem with measurements. These are non-clamped/sealed measurements, so ignore frequency response. All you're looking for are the differences. The mic was in the middle between the two cups, and I did one side at a time. Everything was perfectly still between measurements:

https://www.dropbox.com/s/jo9zjmntpgo4so0/Custom Studio.jpg?dl=0

 

<2db. Looks like perfectly normal Beyer tolerance.
Good ears.

 

It's not as much in the midrange as it is in the lower treble range. It's making them feel lopsided for sure though.

 

Here's a better measurement that shows more accurately how the drivers differ, and how it actually starts diverging at 600Hz. Stupid poopy pants Beyer drivers!

https://www.dropbox.com/s/xdoavged71tvf9a/driver matching CS.jpg?dl=0