Where do you get that notion from? I've heard people say 5dB is insignificant (Tyll's latest Comply article). Then I see studies claiming .3dB is audible. Remember too that dB is logarithmic and we are talking about effects in complex music not test tones.
Btw, are you amping your phones? I simply didn't have the muddled issues you had w/ the EX1000. They aren't BAs but the DD is very articulate. Most articulate DD along w/ the k3003. I'd need to AB to know which is the better DD.