i went through all the threads and posts regarding this topic ...but im still unclear as to any prominent differences among the 3.
does the hd 681b have a better balanced(and thus a 'warmer' feel in the mids) as compared to the standards? does it have more similarity to the 668b sound?
and what exactly is the 681f ??...hows flat different from balanced? ..is there any differences in the neutrality among the 3?






