Thought people might be interested in my impressions of these, since I recently got these for metal listening.
First off, out of the box, I didn't like the sound signature very much at all. That said, I'm very picky about sound signature when it comes to metal.
The EPH seems to have a fair extra emphasis on the lower mid, which I imagine in other genres gives the music a nice "body", but in metal, where this range is often already boosted, it leaves the music sounding congested and dull.
The other issue was that the upper mids seem to be a bit on the reserved side, perhaps to reduce fatigue, but again I find metal works better with a brighter/clearer sound in this register.
And so I went to work with the EQ. Brought down the low end to reduce congestion, brought up the upper mids to highs a bit, left mids mostly intact. If anyone is interested, here is a pic:
http://imgur.com/zwunX6n
Big difference! The music really opened up. So after that, I had a new set of impressions.
* Great instrument separation. Drums are tight and distinct. Guitars float and crunch nicely and distinctly in the mix. Almost every instrument is clearly audible and sounds good, with the intimate soundstage bringing it all into a very involving mix. Hi-hats can sometimes sound artificial/distracting however.
* Vocals sound good with nice body. Not too much to say on that topic.
* Small/intimate soundstage. Can be both good and bad depending on the track. Weak stereophonic effect compared to some IEMs.
* Bass is strong and tight with good impact and accuracy. Could be more detailed however.
* Great build quality and comfort. Tips can be very hard to get off however! Also wish that there was a tactile way to tell left/right apart without looking at them.
EDIT: As I've been informed there is a bump on the left stress relief. Nice one Yamaha!
* Fit can be tricky. Spent a lot of time trying tips initially, since I found that the fit had a major impact on the sound quality. Deep insertion with minimal air between the driver and the ear canal (try pressing the outside into your ears with your fingers) gave the best and clearest sound, but I found this fit too painful and ultimately went with a larger tip and shallower fit, which still sounded "good enough". Occasionally still need to tweak the fit while listening to get the "closer" sound, which can make a dramatic difference. Has anyone tried aftermarket tips that make this easier to achieve with comfort?
EDIT: I found a good sounding and reliable fit by moving one size down on the tips. I think in general for best sound you want the smallest tip that will still seal, as larger tips loosen up the sound undesirably.
So yeah, all in all a very nice little IEM once I got the sound signature closer to where I wanted it. Fairly remarkable for the price actually. I don't have them anymore but I think the next step up that could beat them in some areas is Brainwavz B2, but even then B2 build quality and cable is FAR inferior to the Yamaha.
Anyway, hope that all made sense and helps someone out with their choice
UPDATE:
Having spent a lot more time with them, I'm really enjoying the sound. Rich and interesting, they are a lot of fun to listen to, though they are still not very neutral and as such lacking in versatility without specific EQ.
If anyone is interested, this is the "best" EQ setting I came up with for a lot of Metal:
http://i.imgur.com/F81JYir.png
It brings down the bump in lower mid and bass to give a "decongestant" effect for music that needs it, though it can be too light for more brightly mastered music. Also bumped up the upper mid to give it a bit more energy.
And for context, I believe the poweramp app has a 14db range on the EQ, so I've brought the 500hz band down by ~2.8db for example in that screenshot.
