What’s with the downvotes? Sorry for being one of the only commentators in this thread to have actually tried it, and for saying what happened. There is one other actually, who also says the sound got worse
My point is you should try randomly at least couple of headphones that some other person removed the foam on one of them without you even knowing. Then you could apply some simple test like the binomial, and claim/reject one of them gives you headaches.
Quality of sound has a abjective part (a speaker too loud would sound broken to every one), and a heavy subjective part (a speaker with too much bass would sound great to some, bad to others). If someone say "this headphones sound bad" it means almost nothing.
I hate the sound of every guitar with single coil pickups, even the most expensive Fender Tele/Strato, but a lot of guitarist love their sound. I cannot claim "the single coil sounds worse" as if it was an objective thing that everyone should agree to, because what I really mean is "I don't like single coils".
On reddit, i've written some carefully researched little posts and gotten 1-2 downvotes so i'll downvote myself and see what happens.. sometimes it's a trickle of more downvotes, sometimes i get the upvotes i think it deserved.