Hello!!
I just got a HD250 linear 1 300Ohms from Ebay and I noticed they send it to me without the parts 11 (outside of the driver) and 13 in the picture attached.
The headphone sound is terrible, no bass at all.
Also it came with some Chinesse pads that are honestly terrible. So they might not help neither...
But with this felt disk and without this 13 part (that looks to me like a molded felt) I don't think this headphone can sound great never again...
Do you think there is any way to recover it or find those parts?
Can you upload some picture of the internals of your headphone so I can compare?
Thanks!