*Closest competition: Soundmagic E50, mentioned below*
 
I got these for $15 on Amazon along with the 9100. I think both of these were released late last year. The 8100, pictured here, is an astounding deal. I've used the even more budget-oriented and more popular 3590 as well as the newer 3905 available at Target stores in the US. The 8100, however, has blown me away with their outstanding clarity. The box says "deep bass," which is accurate for the price. These feature unquestionably a V-shaped signature, but one that is more enjoyable to me than their other offerings. I've had some issues with the 3590 and 3900 due to my treble sensitivities. Not overwhelmingly sibilant by any means, but the latter two can sound harsh on some albums I listen to frequently. The 8100 scoops out just the right signature to my ears, with very smooth treble and very punchy bass. The mids are recessed as per usual with V-shaped signatures. But there is absolutely no bass bleed here. These are not going to be described as "warm" by any means, but they feel like they are a noticeable step above in the clarity department. They may even sound somewhat "lean" on some genres. What makes up for the "leanness" is the very punchy sub-bass. What these sound like to me is an intro into the world of higher-end audiophile territory. These are not for bassheads. I have the Soundmagic E50, one of their new audiophile-grade IEMs released last year, and the sound signature of both is VERY close to my ears. So close that I prefer the 8100 due to their overwhelming comfort, as they are really small and just disappear in my ears. Granted, they are not identical. In fact, the Philips' have a notch up on the Soundmagic in the bass department. Perhaps the Soundmagic will have a notch up on detail and featuring a bigger soundstage with more articulate and refined treble. But overall, the two sound surprisingly similar to me. I doubt that these 8100 will suddenly become really popular. As far as I know online is the only place to purchase them in the US, and they are very very cheap on Amazon for the quality you're getting. Both these and the more popular 3590 are excellent budget audiophile earphones. With both you get more than you pay for. I'd expect to pay at least $40 for the quality of the 8100. Unless you crave more bass, the 8100 deserve a mention and a purchase if you dabble in the world of budget audiophiledom. 

How does the E50 compare in the midrange? What about the 9100? I found the 8100 to be quite lacking in the midrange, which is a shame as the bass is quite powerful and treble is rather lean as you described. I think it's still a bit peaked but not fatiguing like the 3900, and cleaner than the 3590, but those two seem a tad less recessed in the mids.