If its out of warranty, you can maybe check this https://www.thephonograph.net/fiio-m11-disassembly/ Good luck

Use oratory1990 via maybe PowerAmp Eq. Band EQ won't be able to fix the sound to that level.

It was broken already in the previous one. The ANC is inexistent nowadays, you go out or commute and hear EVERYTHING. And I used them mostly for metal music. Good luck with other genres

Well two firmwares ago at least it worked

I was out of mine but claimed warranty: The product doesn't work. After explaining the situation and checking nor my unit or the demo unit worked, the owner processed muy return and said they'd check with Sennheiser to return all the units they had left

Did you buy in store? If you paid by card you should be able to get a receipt. Otherwise, try to talk to the store, explain you don't have a receipt and try to go by Sennheisers warranty. The ANC is inexistent, you should be able to just return them claiming they don't work. I had no problems at...

You can do what I did. Return them. I didn't care to get them again but guess if you buy them again they'll come with the original firmware. I was too pissed off to try to do a reverse lookup and force an old firmware but might be possible too.

Yeah they touched that already in the previous firmware. Totally destroys the ANC at any levels. So the M4s are good sounding wireless cans with no noise reduction. Edit: Good sounding after EQing via parametric EQ of course

So far I think there's only one hardware version being sold. 4.0. It doesn't matter if you bought it on launch day or last week. I don't think the headphones sold any good for them making new batches. About people buying them already with the latest firmware, that's something normal in most...

"Thanks for your request. A downgrade is not possible, but there will be a big update coming in +/- one week which will solve a lot of problems and also have new features." they told me on March 10th 🤠

Did you try them with the latest firmware? And is the new firmware out, or September 2022 is still the latest?

It's April 31st. 100% confirmed.

Hey guys, good news :D I mailed Sennheiser again asking what did they mean with +/- a week and got a new answer! According to the development department the update will be "coming soon"... :wave:

Its the latest firm that introduced most issues No