Pros: Detailing, comfort, accessories, build quality, tight bass
Cons: Low overall sound quality, messy mids, metallic sounding highs
Just want to state up front my review rating is an absolute rating, not one based on comparative performance, pricing etc.
Having had the Shure SE215s for a while and not enjoying them I thought I would go up the range and try the SE315s. At first I was impressed as the nasty spiky highs and wooly bass seemed to have gone but alas it was not to last. My overall thoughts are:
Highs: Good detailing, much better than the SE215s. Can get a bit sibilant but mostly are under control. Can sound a bit 'metallic' at times and if you get ear fatigue with bright earphones then you may want to audition these first. I did not find these as bad as the SE215s but they are not hugely improved.
Mids: Again some good detailing but there seems to be a complete lack of depth. I tried these with different tips and there was a slight improvement on this front going with the silicone tips but not much. I felt the mids were really muddled and some instruments came through nicely and others stayed mixed with others. Overall the soundstage felt narrow and flat.
Bass: This is where I feel Shure have made the biggest improvement over the SE215s. Detailing, particularly in the mid bass, was much more insightful. There was a good extension but never boomy. These are fairly bass light so bass heads steer well clear!
Overall: With certain more laid back types of music these perform well. However their tendency to make highs sound unnatural combined with a very narrow and shallow soundstage make these a non-keeper for me. In this price range there are some cracking earphones with a much better overall sound 'quality'. These sound too forced and metallic for my liking. Shame :(