Read a ton of reviews before purchasing. However, I will be honest and say that I was a bit let down by the bass. Don't get me wrong, its very detailed and balanced and perhaps there lies my issue, I was under the impression that these were more bassy. I am a bit of a basshead, in that, I like to feel it. Obviously, to many these have plenty of bass and the upper bass is there but it diminishes as it gets deeper to my ears which surprised me, again due to reviews. For the vast majority of what I listen to the bass is fine but for electronic stuff there is near zero rumble where there should have been. This could be due to the fact that I cannot insert them but rather rest them inside using the largest tip for a seal which itself is very vague(fit), perhaps due to the thin silicon used. My theory based on other reviews and my findings is that there is simply too much air volume between the driver and my ear drum to get deep bass. Really this is the only thing I have an issue with.
UPDATE: I finally figured out what I needed to do fit wise. For some reason the smaller tip would not seal despite being a very tight fit and realized the L tip was required but still needed to be inserted which takes a bit of actual force. The comfort could be worse but could be better. But inserted with the large tip does deliver that elusive bass response. Sealed, it really hits hard. Matter of fact I just got the PannyHJE900 known for its Monster like bass and the Yams are very similar. It is just that the Panny just sits there and it seals.
Mids are very engaging. Not recessed at all, nor are they affected by bass bleed. They are not warm or particularly thin but really detailed. I hear things I never noticed before and they kill my old Klipsch X5 BA IEM. This is the earphones strength IMO.
UPDATE: Just got the Panasonic HJE900 and they are both really quite similar in that both are very quick, clear and both use a micro driver.Neither would I describe as thick or warm but not cold either. This gave me further insight to the Yamahas mids which decimate the Panasonic. Not that the 900s are bad, they are recessed and not even that badly. I guess what I am saying is that it is true, most of the music is in the mids. I am listening to psytrance and both deliver on the beat but all that cool sound effects flowing about in stereo is much more clear on the Yams. This only helps to draw me further into the soundscape. More immersive and enjoyable. The Pannys make that all sound a bit distant. This is really what sets the Yams apart because it is extremely common to have the V shape sound with the exception of flat, analytical but boring IEMs. The Yams have that dynamic fun sound while still able to deliver all that musical info often overwhelmed by other fun IEM.
Treble is also really good but not up to the mids level. I am hearing cymbals that I never heard before and they have there own realestate like all the instruments through these things which only helps with detail and complex metal music where everything is loud. To be nit picky they could have some more splash or just a bit more forward after hearing my Panasonic HJE900(which is too bright).
Finally, I am still surprised what a tiny dynamic can do. There is mucho detail but these are on the fun side rather than the analytical side without being too soft or warm. An IEM that makes you want to listen to every album again to see what you missed before. I came from Klipsch X5 and have the SoundMagic HP 100 and they don't approach the Yams for insight and resolution. However, the fit and weak sub bass makes listening to electronic stuff a bit conflicting because they really draw you into the sound with their detail then the sub bass comes and I am left hearing it buried by everything else with zero rumble. I must keep reminding myself that bass is perhaps the most conflicted aspect of sound as everyone has what they think is too much or not enough. That for some audiophiles, apparently being able to actually hear the bass drum is fine and forward bass. Also, many never listen to electronic music where sub bass is a must and therefore don't notice it as much.
UPDATE: The bass is no longer a real issue as I have finally figured out the correct fit. I still could use more deep sub bass but then that is hard to find on any IEM. I am accustomed to the Soundmagic HP100 which is blessed with incredible sub bass. It is literally as loud at 40Hz as it is at 100-150HZ.
