Originally Posted by wink
There's also the fact that one person's opinion is that it sounds good, whilst another listening to the same setup will say that it's rubbish
Yet, both people listening to the headphones properly driven would say that it was great.
What the heck does that mean? The whole point is "properly driven." That doesn't necessarily mean super-low output impedance in every case. If that were so, neither OTL or transformer-coupled tube amps would ever enter the picture with audiophiles. Yet they do ... and literally prosper.
Technically speaking, it's possible to over-damp. Every oscillating system will have a critical damping factor. By definition of a critical point, that means there are scenarios on both sides that are not at the critical point. IOW, there are under-damped and over-damped scenarios.
The entire race for a high damping factor pre-supposes the assumption that every single headphone driver will react the same to ever-increasing damping factors. It may work in a lot of cases, perhaps even the majority. Yet, it's also a bit like saying every headphone ever made is the same.