Greetings all, I have 2 sets of AKG K702 and they sound different from each other. The set that I wonder about has a bit of a scoop in the upper bass, my rough guess being that it's between 250 and 400 Hz. The 'good' set - the one without the scoop - sound more accurate to me - more linear - on...

What in the world FiiO! Received the M11 Pro about a week and a half ago in the mail - turned it on to find a residual "ghost" image. A curved rectangle that was just always there. Returned it. Received the M11 today, same thing! The rectangular outline is slightly less prominent, but two...