Defected put a good post up about sound levels and your hearing.
It got me thinking about so many times I’ve either gone through the doors and instantly thought it’s too bright / harsh on the highs (and the people working here aren’t calling the sound engineer or DJ out on it because their ears have been exposed to it for months / years, their hearing is already damaged).
I think the best venues have speakers around the room, set at a medium level, instead of a stack at the front that have to be pushed hard so the back can feel it (damaging the many who are enjoying themselves at the front).
It’s interesting how your ears adjust too so when it is harsh, if you put up with it, that seems to calm down and your ears are ringing on the way home - I always used to think that was the sign of a good night!