Hi I'm trying to improve our headphone situation. Basically I'm finding that the headphones (DT100's) :shock: distort at what I'd call medium volume. We have six pairs of these and they all seem to do it. I'm driving them from a Behringer powerplay headphone amp in mono. I'm wondering if headphones distort at different levels according to how their impedence match the amp. Also I've tried driving the headphones from the desk's (Mackie SR series) aux sends directly via a connection that sums their output to both ears. The results are very similar. Any tips for finding the weak link?