Wanted to chime in with some thoughts on the XBA-4s that I purchased about a month ago. When I first received these headphones I was pleased by the "punchiness" of the sound but wasn't immediately blown away. I too noticed the "metallic shimmer", particularly on any songs with horns and certain female vocals (strangely enough, Taylor Swift's vocals seemed to be particularly impacted, but I digress).
I am not usually one to fiddle with equalization of my sound (more out of laziness than any other reason) but on a hunch, I paired these buds with an old Caffeine amp that I had laying around, with the bass boost turned on. I was immediately blown away by the sound - with the woofers fully engaged, the XBA-4s took on a whole new character and their fun factor immediately went through the roof. I was able to duplicate the effect with a mild bass boost using software equalization on my player.
The earphones respond very well to a low-end bass boost and the sound became noticeably fuller as the XBA-4s are capable of delivering both a very satisfying low-end and still retain clarity in the mid-range and the high-end. Interestingly, with the bass boost, I have also noticed less of the "metallic shimmer". I am not sure if it is being masked by the bass or if there is some kind of interplay between the frequencies, but suffice to say, I am now a very happy camper with these buds.
Something to try for those of you that are auditioning these buds or already have them, to see if a bass boost results in a sound signature that suits your preferences!
