Planar magnetic drivers chassis buzz and resonance issues

[SiegwardZwiebelbrudi]

Edition XS, Fiio TF1 Pro
Topping DX3 Pro+

I have had three pairs of PM Headphones at home until know and each of them displayed some sort of resonating noise in either the chassis or the driver itself.
I use this tone generator and with all three i found frequencies that agitate some sort of resonance noise at loud volumes. this was less of an issue with the FT1 Pro, since i couldn't replicate this in a real world listening scenario, but with one Edition XS this happened at 440hz and i had several songs, especially with brass instruments or synths, that you could simply not listen to with the Edition XS in question.

Whats the issue here? i have never had a comparable issue with dynamic drivers, is is the membrane size that makes it prone to noise/buzzing? Anybody experience similar issues?
I love the Edition XS, but i returned them, because i don't trust Aliexpress with handling warranty. i will now buy them a lot more expensive from a german retailer, but i would really like some insight.

I have not double checked with another amp, but it really seems to be a physical issue with the drivers itself, as it could be, at some frequencies, be alleviated by pressing on the chassis

very much like this guy here on reddit experienced.

https://www.reddit.com/r/HeadphoneAdvice/comments/v50hid/hifiman_edition_xs_3_out_of_3_rmas_have_defective

 

[swamps]

Hmm it seems to be a problem on the driver itself, maybe the membrane is slightly touching the magnets because the suspension is warped. This buzz can happen on dynamic drivers when the diaphragm gets damaged and stays warped, but it's usually worse the lower the frequency.

If the XS looks anything like the XX from this thread https://www.audiosciencereview.com/...hifiman-edition-xs-unbalanced-channels.39619/
then it really may be a warped suspension.

Is this buzz only around 440hz or does it happen at lower frequencies if you turn up the volume even more?
And can you try pressing that area around the membrane and see if it mitigates the issue like that reddit guy did?

 

[SiegwardZwiebelbrudi]

Hmm it seems to be a problem on the driver itself, maybe the membrane is slightly touching the magnets because the suspension is warped. This buzz can happen on dynamic drivers when the diaphragm gets damaged and stays warped, but it's usually worse the lower the frequency.

If the XS looks anything like the XX from this thread https://www.audiosciencereview.com/...hifiman-edition-xs-unbalanced-channels.39619/
then it really may be a warped suspension.

Is this buzz only around 440hz or does it happen at lower frequencies if you turn up the volume even more?
And can you try pressing that area around the membrane and see if it mitigates the issue like that reddit guy did?

for me it was 440hz where i noticed the issue, but all three headphones had some kind of iisue with buzzing at different frequencies. didn't happen at higher frequencies, what was to be expected, since the energy is just lower. I ordered a second FT1 Pro to compare. Edition XS would be my preferred choice, but the issues where a lot worde with those