First, apologies for the wall of text, I didn’t have time to write it short. And also apologies because its not a great review as much as it is a personal head-fi epiphany, so if you find this useless or dull, you have been warned J.
So I wasn't too impressed with the RE-ZEROs that I purchased a few months ago. I found them to be thin and cold with too much upper/midrange that completely shrunk the soundstage and made all the music I threw at it sound unnaturally hallow. I did notice that they had excellent detail in the highs and great resolution overall, but the sound was the farthest thing away from fun.
I have since then purchased the Sony MH1Cs which I feel are just great, all-round warm and fun headphones and I have paired them with my new Fiio E11 amp. After enjoying the Sonys and learning more about the nuances of getting good sound out of IEMs, the head-fi bug bit me again. Yes, the grass is always greener here, and I too fell to the siren song of "but if you could just find an IEM that had the warmth of XX but with better highs you'd be even happier." The only headphones that were within my price-range that I knew had that kind of resolution in the upper frequency is the RE-ZEROs or the RE0s. So I decided, hey what the heck, what's another $5 return fee and I decided to pick up the RE0s while they are on sale.
I had anticipated the same issues I had with the RE-ZEROs and I was prepared to defend against the hallow sound with better tips, a somewhat greater understanding of EQing and an amp that has a bass booster to warm up the sound… not sure if it would be enough to make them sound as warm and fun as the Sonys.
After putting on my favorite tips (Sony hybrids are just amazing), cranking the Fiio booster to 2 and strapping on the RE0s, I must say I am pretty blown away by the amazingly warm and dynamic sound that emerged. What I hoped for was the Sony sound with better highs... what I got was even more detail in the bass, greater resolution, a lifted veil on the mids and better highs. In fact, the RE0's also EQ extremely well, even taking extra bass from the crappy WMPlayer EQ and keeping the sound tight. I now understand why the RE0's are so well regarded on head-fi by those in the know, because detail and a flattened sound signature is key to overall good sound quality because they give you a much better starting point to work from to then dial in the sound you really want.
So if any of you are looking for more detail then you get from the Sonys but don't want to spend much, the RE0s are a worth seriously considering IF you have a warm amplifier like the Fiio E11. If not, these just won't give you that type of dynamic warm sound.
TL:DR : RE0's are a major step up from the Sony MH1C if (and only if) you use a warm amplifier with them. And they are still available for $50.
EDIT: Wanted to thank the head-fi community and especially those who've given all of us such great information like Joker, ClieOS and Joe Bloggs to name a few. Without them, I doubt I would probably not have been able to enjoy IEM audio like I now do.
Edited by bhima - 11/29/12 at 3:38pm