Hello, I remember how previous summer I was playing on a Killing Floor 2 RPG Mod server with max audio and I was very comfortable with it, now it's kind of uncomfortable to do it again, what could be it from? I don't feel ear pain or anything, it's just not comfortable, I'd rather listen to the song at 40% audio now and I want to play such games with max audio and have fun time.
I wouldn't recommend listening headphones with loud volume. You can permamently damage your ears, and there no cure for it. Reason you are not comfortable with loud sound could be that sound is cracking and quality gets very low. Another reason is that you just got old and dont feel "rush" by playing on loud volume. I think this is very good thing you are more comfortable with lower volume. I would strongly suggest to keep it. EDIT: If you want to have fun with sound and headphones, try Dolby Headphones. Its a feature in some soundcard that give you impression of surround sound.
I do feel this "rush" you're talking about but can't that much because the music isn't loud enough. I guess I'll stay with lower volume, thanks.