This is more of a general audio question, but still relevant I feel.
I have had my HD 600 for about 5 years now and noticed channel imbalance sneaking in slowly. Now it is noticable, but not too bad just yet. I was hoping for more expensive headphones to not have these issues, but apparently I was wrong. Is this just something one has to get over, or is there some secret sauce to prevent this from happening?
I have now gone through some classic budget IEM recommendations as well and they have all had severe cases of channel imbalance in a very short timespan:
Salnotes ZERO (about 3 months)
Moondrop Chu (about 0.8 months)
KZ ZSN Pro X (this one took 6 years to get channel imablance actually)
Will I just have to get new headphones now? I'm eyeing those Beyerdynamics everyone talks about (DT 770 pro).
EDIT: Also, I have found that it tends to be mostly the harsh frequencies which shift over to one side, so when adjusting the balance in some settings, it shifts all the other frequencies out of balance while fixing the 4000 - 8000 into the right position. Just something I observed.
I habe already flipped the headphones so it's nit my hearing (I'm also pretty young so yeah). I will try another DAC at home today, so I'll update this comment once I do that.
Being young doesn't really matter as you can also damage your hearing if exposed to loud sounds, but I digress. Regarding channel imbalance. If your amplifier uses old school potentiometers channel balance is certainly a thing. So you indeed need to test that imbalance with other sources. Also I have been enjoying music since my teens and I'm now in my forties, imbalance with headphones was a pretty rare thing for me, as for IEMs besides the rare QC thing I never had that kind of problems. I know it's a long shot but you should test your amplifier section for DC offset...most amps filter it but one is never too cautious as it can ruin gear.
I tried my HD 600 at home with different dacs (two ones from Fiio) and they both game me that same channel imbalance which shifts higher tones to the right. So unfortunately this seems to be a headphone thing. I meam/, they served me very well for the last four or five years, I used the loads. I guess its time to get some new ones.. And also I'll look I to cleaning my IEMs.
If you still want to use those HD600 and are into DIY, you can buy a matched set of drivers from sennheiser and replace those old drivers. Also if you feel comfortable and have the time, do open up the headphones and check if the drivers don't have any foreign materials on them, like hairs etc, as that kind of stuff can impact driver performance. Yes, cleaning IEMs is certainly a thing, they do get clogged as time goes by. Have my best regards and enjoy your music. 🎩