Major Edit: The cable on one side partially shorted-out. Details below.
So first of all guys, I managed to get these for an
incredible deal of only $50 at this site: http://www.shopdivvy.com/products/puro-sound-labs-iem500-studio-grade-in-ear-monitors-with-dual-dynamic-drivers Pretty amazing, considering they go for over $120 on Amazon! Anyway, moving on to the actual review:
These are great! They have both pros and cons compared to my other IEM's, the Trinity Delta and the Shure SE215, which I will go into in the comparison section below. So, to get started, let me go through category-by-category:
Value
For the price of only 50 dollars that I paid for these, they are insanely good. That's all I can really say in this regard. I honestly feel that even for the price of $120 on Amazon, though, they are still quite a good value
Sound
Overall Impressions: These have excellent clarity and detail, a very neutral signature (which can be just a tad bright at times, however) but with powerful and well-extended bass when called-for, crystal clear sparkling highs with excellent extension, and a nice soundstage with fantastically realistic imaging. They also have great speed, it would seem. My one complaint would be that while these have fantastic detail and clarity, those aspects of the sound seem to come at the price of "smoothness," so that the sound can sometimes be a bit rough and unforgiving, at times even fatiguing (although not to a degree that detracts from my enjoyment). Now, in order by category, in more detail:
Bass
Well-extended and very tight, without a hint of bloat, it is subtle but always audible on tracks without heavy bass, but able to become punchy and powerful on tracks where the bass is prominent, very much in keeping with the overall neutrality of these IEM's. It doesn't really "stand out" like the bass of other IEM's I have heard, but is there when needed, and I enjoy it.
Mids
The mids are wonderfully forward, giving vocals and the majority of instrumentals a very pleasing and musical "in your face" kind of quality which usually sounds quite natural. Not much more can really be said about the mids except that the
upper mids (bordering on the lower treble) can, at times, become a bit strident and ever-so-slightly fatiguing. . .this may just be due to me having very high-sensitive ears, however, as I do recognize that overall, these are quite neutral.
Treble
These really stand out in the treble. Wow, it's so crystal-clear and sparkly, guys! The extension into the upper-octave is quite excellent and gives a fantastic "shimmer" to things like cymbals and high-pitched harmonics. However, just like the upper-mids, the lower-treble can, at times, become just a little bit strident and fatiguing to my ears. . .meh. Nothing to worry about though, especially once my brain gets used to it

The treble seems to be at
about the same volume-level as the bass and mids, again in-keeping with the overall neutral tone of these.
Clarity and Detail
Holy moly!!!! These things sound like pure crystal. It is fantastic for well-mastered tracks. On the other hand, it is a bit unforgiving of more average-quality source material such as a lot of rap and hip-hop, but even then still sounds great to my ears

The clarity is to such an extent that it can sound almost "rough" at times, in keeping with the quality of recordings and how they are mastered. Also, it seems to achieve such clarity at the cost of some of the smoothed-out "musicality" that I enjoy so much in other IEM's, as elaborated upon in my comparisons below. I'd say that this is both a pro AND a con of the sound of these IEM's. It is fantastic with very, very well-mastered music, and absolutely superb with classical/symphonic/orchestral pieces. . .now that I have these, I will not use anything else that I own for listening to Bach or Beethoven, for example
Soundstage and Imaging
The soundstage has decent width but is overall intimate, but pretty darn impressive depth that gives a good feeling of separation between instruments. Color me impressed, as far as dual-driver IEM's go! Meanwhile, the directional imaging is incredibly precise and realistic, and a real strength of these that is another reason I absolutely love using these for Classical music.
Speed
Truly excellent for dynamic drivers. Nothing ever seems to "blend together" very much, not even in the fastest of heavy death-metal and thrash and such.
Design, Build, and Comfort/Fit and Seal
Well, these are pretty cool-looking, I must say, although they do tend to "stick out" a bit from the ears more than some other IEM's. But the knurled aluminum housings are pretty darn cool looking, so I don't mind
Meanwhile, the actual build of the housings feels very, very sturdy. HOWEVER, my one gripe with the build would have to be the cable. It seems very thin, and is not confidence-inspiring in the least. With a cable this thin, I wish they had made it detachable. That being said, once shouldn't just a book by its cover. . .for all I know, the wiring on the interior of the cable may be of the highest quality! I suppose that only time will tell, really. Also, the cables get darn bad microphonics when worn cable-down, however it is very easy to wear these in an over-ear style and that solves the problem almost completely.
These are very comfortable! Nothing more really needs to be said in that regard. After a while wearing them, they really seem to "disappear,' so to speak. However, I had a hard time getting a truly proper seal with any of the tips that came with the IEM's, despite them coming with five different sizes of tips! I don't know if this is due to the quality of the tips, the size of my own ear-canals, or what. But, I was able to fit these easily with the medium-sized silicone-rubber tips from my Trinity Deltas (I use the double-flange tips with the Deltas, so I could spare the normal silicone ones), and with those I manage to achieve IDEAL seal and comfort from the IEM500's. I would certainly recommend investing in some good aftermarket tips for these for many folks.
Major Update/Edit: Just as I had feared, the flimsy cables were an issue. The cable on one side shorted out (causing the music to play about 12db quieter on that side) after about four months of fairly steady use. Not good build quality for the non-detachable cables. For this reason I had to bump it down to four stars. I only bumped it by half a star because I did get them for only $50. But still, it seems silly of them to put a sophisticated dual-driver sound like this in a really nice housing, but with poor quality non-detachable cables.
Isolation
Again, HOLY MOLY! I don't know how they made IEM's with vented dynamic drivers that have isolation this good! It's really quite remarkable. Once I get the music going with these, I can hardly hear ANYTHING in my surroundings, they isolate almost as well as the Shure SE215!
Microphone Quality
To be honest? No idea, and don't care. Sorry guys
Comparisons
I have experience with two other better-than-average quality in-ears that I can compare these two: The Shure SE215 and the Trinity Delta. So, here goes:
Trinity Delta
I'd have to say these have both advantages and disadvantages compared to the Deltas. They don't seem quite as well-built overall, especially the cables. They do not have adjustable filters to change the sound-signature like the Delta. The Delta, with stock or silver filters, have an overall warm (in the gunmetal case, TILTED towards almost neutral) signature, while with the purple filter are bright. I'd say that the signature of the Puros lies somewhere between that of the Deltas with the gunmetal and the purple filters, right in the midst of "neutral-land." The bass doesn't have the actual quantity it does from the Deltas with the gunmetal or silver filters, so they aren't as good for music like rap, hip-hop, and funk, but on the other hand I feel they do a good bit better with purely acoustic stuff and symphonic music, as well as many genres of rock and blues. And it's not like the bass doesn't have impact, they just aren't warm/bass-boosted. . .but the bass is able to have powerful punch when called for. They have more clarity and transparency then the Deltas with any of their filters (very noticeably more clarity than the Gunmetal filter Delta, and a subtle but still quite noticeable increase in clarity and detail over the silver-filter Deltas), but at the cost of that wonderful "smooth" timbre possessed by the Deltas, so it's a trade-off in that regard. The soundstage seems about the same, while I'd say the directional imaging of the Puros is actually ever-so-slightly better than that of the Deltas and is a real strength of theirs. Comfort is about the same, although it was easier to achieve a proper seal with the tips that came with the Deltas. The Puros get worse cable-microphonics than the Deltas when worn cable-down. The Puros do manage to isolate noticeably better than the Deltas, and I certainly prefer them in noisy environments. Finally, the Puros are faster, and cause less "blending" of details in very very fast, busy tracks.
Overall, I'd say I don't prefer one of the two over the other, but rather prefer the Puros for the most well-mastered music which also benefits best from true neutrality, while I prefer the Deltas with any music that can benefit from a bit of "smoothing," as well as any music that sounds best when given a bit of a warmer coloration.
Shure SE215
Just like the Deltas, I'd say these kick the crap out of the SE215 in every single way while being in the same general price-range. The only way they fall behind the SE215 is in terms of their isolation, and in terms of the impact/quantity of bass. The SE215 are quite warm and a good bit bass-boosted, while these are neutral. The SE215 do isolate even better than the Puros, and are better in the noisiest of external environments. In terms of isolation, I'd rank the three: Shure SE215>Puro IEM500>Trinity Delta. Like the Deltas, the SE215 are "smoother" and not as rough sounding as the Puros, but unlike the Deltas they are SO MUCH LESS clear and detailed that I much prefer the Puros over them for just about any genre. The Puros have a better soundstage than the SE215, and somewhat better imaging.
Don't get me wrong, the SE215 are definitely some good IEM's! It's just that the Puros and the Deltas are so much BETTER
Overall
These are really great, guys! There's nothing more I can say here that I haven't already said. Great clarity and detail, very neutral but perhaps a tiny bit strident at time, they have powerful bass when called-for and subtle bass otherwise, nice natural sounding mids. They are fantastic for Classical orchestral music as well as acoustic, and for rock, blues, and jazz that sound best on neutral equipment.
Major Edit for those who missed it earlier: The cable on one side shorted out (causing the music to play about 12db quieter on that side) after about four months of fairly steady use. Not good build quality for the non-detachable cables. For this reason I had to bump it down to four stars. I only bumped it by half a star because I did get them for only $50. But still, it seems silly of them to put a sophisticated dual-driver sound like this in a really nice housing, but with poor quality non-detachable cables.