HEAD-DIRECT RE0 In-ear Headphones Reviews

I'm not great at writing reviews, but I'm bored right now and I thought I'd take the time to "honor" the RE0's. I've bought/sold/heard many IEM's in the past, stuff like: IE8, W3, PFE, SE530, TF10, X10 etc. Before the RE0's went on that $99 sale, I came to the conclusion that the W3's were the IEM's for me, X10 and SE530 came in a close second, but anyway, my point is, I was quite satisfied with the W3's until I decided to give the RE0's a shot. At first, I was really missing the bass of the W3's, the RE0's sounded a bit thin compared to them. I was disappointed but I didn't give up on them. I burned them in and kept listening. Eventually, whether it was my mind adjusting or my taste changing, I realized how refreshing the RE0's sounded compared to the W3's, it was like a splash of cold water after walking through the desert. I was no longer missing the coloration of the W3's, I felt like the RE0's were the most natural sounding IEM's I've ever heard. Highs extend effortlessly with no signs of fatigue or harshness. Female vocals really shine. They may disappoint bass-heads, but for anyone who strives for true audio reproduction, this is the IEM for you. The bass is there and it's accurate, it's quality, but it just lacks that visceral impact that some IEM's provide (IE8 comes to mind). They can really rock out too, quite a dynamic sound with great PRAT, instrument separation is fantastic and the timbre is spot-on.

In conclusion, for me, this was the IEM that stopped my search/interest in the next FOTM. And what shocks me the most is, it's pretty much 1/3 the price of all the other IEM's I've tried. Incredible value @ $79, actually, it's an absolute S T E A L, I highly doubt you can find anything better for the price, or even double/triple the price. Of course, YMMV, but this is my experience.

Introduction

I’ve already written a great deal on the RE0s but I don’t consider any of it a formal review in the traditional sense. If you’ve read my previous writing about the RE0s, you should know that I am positively enamored by them. In the few weeks since I received them, they have quickly become my preferred listening devices when I sit down with my laptop or iPod and listen to music. After putting them through their paces for 200+ hours and listening to the sound signature evolve and mature in that time, I finally feel that I’m ready to give the RE0s the review they deserve. So, without further ado, read on for my full review of the HiFiMan RE0 in ear monitors.

Technical Specifications

Driver: 9mm dynamic driver
Frequency Response: 15Hz – 22KHz
Impedance: 64 Ω
Sensitivity: 100db/1mw
Cable Length: 1.28m/4.2ft
 

Packaging and Accessories

The RE0s come packaged in a small, clear plastic clamshell box. The design is unobtrusive and eye catching, showing off the IEMs flanked by the three pairs of silicone single flange tips. Included accessories range from the aforementioned three pairs of single flange silicone tips, two pairs of small and large bi-flanges, five pairs of replacement filters and a shirt clip. Overall, this is a decent accessory package but I would’ve been happier if a soft or hard carrying case had been included with the package. I guess you could argue that the case the RE0s came in could be used to carry them around in a pinch but it’s just slightly too big and bulky to fit very comfortably in a pocket.

Design and Build Quality

Right off the bat, the similarity to the V-Moda Vibes is immediately apparent. The housing is made of metal, painted black with a matte finish instead of the high-fashion polished aluminum look and feel of the V-Moda Vibes. The metal design inspires confidence in terms of long and short-term durability in that they feel sturdy and resilient without being too heavy or too light. Extending down from the casing is a long strain relief which is soft rubber in texture and adds to the durability and protects the cable as it enters the housing. The cable also terminates in a properly relieved L-plug which is new in the current revision of the RE0s.

The cable itself is relatively heavy, fairly thick and very soft and pliable. It seems durable enough to withstand a fair amount of abuse. One issue I have with the cabling of the RE0s is that they transmit a lot of cable noise. Wearing them straight down while walking or performing any kind of activity that causes the IEMs to rub against your clothing, will result in microphonic noise being transmitted into your ears. It’s annoying and distracting to be sure and using the included shirt clip and wearing them over-the-ear is practically required if you plan on walking with these.

These feel like they will be able to withstand normal amounts of daily use and abuse for a long period of time. I do wish these came with a carrying case of some kind to protect them while on the go and naturally, it’s expected that you’ll want to protect your investment. I would advise investing in a carrying case of some kind to protect them if you plan on carrying them around.

Comfort and Fit

The housings of the RE0s are very small and light and, as such, you’ll barely feel them while they’re in your ears. For me and my small ear canals, the small black tips were best for me but now, I use a pair of small tips I sourced from a pair of V-Moda Vibes which I find to be a bit softer and thus more comfortable. With all of the various eartips supplied with the RE0s, I’m sure that most users will be able to find a pair that work for them.

Sound Quality

Let me preface this by saying that these are the best sounding IEMs I’ve ever heard. Nothing I’ve ever used comes close to matching the RE0s in terms of clarity and transparency, bass and treble extension and micro level detail. These are a highly resolving pair of IEMs and as such will be highly revealing of flaws in your source material. I would not recommend using these with 128kbps music files or any other poorly recorded music, as these will make the flaws in those files stand out so much more. On the other hand, because they are so highly resolving, they allow great recordings and high bitrate files such as 320kbps MP3s and FLAC files to shine.

The RE0s are a very neutral pair of IEMs across the board and offer very little in the way of coloration to the music being pumped through them. These are highly transparent and allow you to hear music mostly as the artist intended, without adding any degree of warmth or coldness that isn’t actually present in the piece itself.

The midrange is fairly recessed but lively and very clear. Both male and female vocals are full-bodied and natural sounding and, across the board, instruments just sound great. The biggest strength of the RE0s is their endlessly extended and exceptionally clear and bright treble. Highs are forward and sparkle with just a touch of warmth without a hint of sibilance. These have the best highs I’ve ever heard in an IEM and should please just about anyone looking for a great high end response.

Low end response is perhaps the weakest aspect of the RE0’s sonic presentation but even then, it’s not at all bad. Bass is very detailed and natural sounding but what it lacks in is body. It just doesn’t have quite enough “oomph” to my ears and as a result makes the entire sound signature somewhat thin. Extension is very nice as well, as you can detect bass notes down to 20 Hz, even if those notes aren’t particularly powerful.

Soundstage and imaging are both good as well. The soundstage is of average size and depth, with great instrument separation and decent imaging.

The RE0s don’t necessarily need an amp, despite their relatively high 64 ohm impedance but respond very well to the extra juice. The soundstage widens a bit, dynamics improve and the bass improves a bit in terms of fullness. These also respond well to amps with a bass boost feature such as the inexpensive Fiio E5 and the JDS Labs CMoy BB, which highlight the great low end detail and sub-bass extension the RE0s possess.

Conclusion

Without a doubt, these are the best IEMs I’ve ever heard. These really make my music collection come alive and are very entertaining to listen to for long stretches. They let the music sink in slowly if you’re reading a book, doing homework or anything else that requires concentration while also allowing you to tune into the finer details of the music and really immerse yourself in the music you hear. For the current asking price of $80 plus shipping from Head-Direct, you really can’t go wrong with the RE0s. While these probably won’t satisfy bass-heads (at least without a bass boosting amp), these can easily compete with IEMs three to four times their price and are an absolutely phenomenal value for the price. I highly recommend these to budget conscious audiophiles who are interested in neutral and, above all, excellent sounding IEMs.

Re-Posted From My Site Musical Musings
 

The RE0 has been available for several years now and therefore it has had time to penetrate the Head-fi community and generate a range of comments on it's performance as a moderately-priced IEM. After reading various threads and reviews myself, I came to the conclusion that their qualities probably outweighed their liabilities and recently purchased a pair. After a month with them, was it a good decision? In a word, yes, but with a few caveats.

Off the top, I would say that the RE0 is probably not going to match everyone’s listening preferences. The often repeated comment that they are bass-light, is generally a fair statement. Nonetheless, when listening to music with isolated bass, the RE0 quickly demonstrated that it was capable of delivering accurate bass easily. What others have said (and with which I completely agree) is that the RE0 lacks bass impact or sustain. In a musical context, therefore, the mid- and treble frequencies of the RE0 can dominate the bass producing what is often referred to as an analytical sound signature. Is this enough to kill the RE0 as good IEM? Not to my ears, because I don't listen to music that is overly bass-centric. Small group jazz, acoustic roots and blues, female vocal, solo piano, classical guitar are just some of the genres that will shine through the RE0. What the RE0 does deliver in spades is pin-point clarity of instruments and vocals that are accurately imaged and presented on a surprisingly wide sound stage.

Several other points are worth mentioning regarding the overall sound quality of the RE0. Indicative of any quality headphone or IEM the RE0's benefited substantially by:

• a burn-in period

• a quality source

• enough amp support

These factors unquestionably affect all IEMs, but I found this to be particularly true for the RE0. Right out of the box they did not impress, especially from a portable DAP playing low bitrate files. However, within 20 hrs. of burn-in the sound quality became much more balanced, the bass less attenuated in its presentation. Music files also need to be at a high bitrate (320k - 350kbps), if you’re not going to a lossless format. Although the RE0 is marketed as an IEM for portable devices, its nominal 64 ohm impedance indicates that it really benefits from additional power beyond what my Sansa clip can provide. This is based on how much better the RE0's sound through my Sony laptop and makes me consider that the RE0 would scale-up nicely with a desktop amp.

Regarding other issues like build quality, in ear comfort and noise isolation, I have had no problems. Every IEM requires a bit of experimenting to get the best fit. The bi-flange tips are quite soft, although for me the medium rubber tips and worn over-the-ear provided the most comfort. Noise isolation, however, is only average at best, which may be an issue if you intend on using them in a noisy environment.

At their currently listed retail price of $79.00 from Head-Direct, I believe that in the right musical context, the RE0 continues to provide outstanding value in a IEM.

These are easily the best earphones I've ever heard. They out-perform both of my older sets of cans. Admittedly, they're older headphones, but they're AKG and Sennheiser cans that were worth equivalent money or better than the Re0s so, to me, that's impressive!

The Head-Direct and Hi-Fi Man brands are one and the same so don't be thrown by the different references. If it says Re0, it's the same earphone regardless of which brand you read on the review.

The Re0s are a 9mm dynamic driver canal phone. They are a simple and plain design which belies their spectacular sound.

The specs don't really jump out:

• 9mm dynamic drivers with neodymium
• 64 Ohm impedance
• 100 dB/1mW sensitivity
• 15 - 22,000 Hz range

Sound Quality

I used to work for a hi-end audio-visual manufacturer and one of the key lessons from my time there was that the first impression of an audio or visual source is not accurate. The TVs and speakers that we often go for first are the most dynamic or bright, but almost never the most accurate. These dynamic sources seem exciting at first, but will quickly become tiring. The natural, true-to-life sources seem dull, flat and boring at first, but in time our body adjusts to these (and we stop comparing them with other sources) and we discover the subtleties and balance that make them truly special. The Re0s are one of those balanced, natural sources so give them a chance when you first get them. Get to know them so they can knock your socks off when you least expect it!!

The sound from the Re0s is pretty close to perfect. Detail is amazing, mids are realistic and bass is present, but never over-stated. The sound is smooth, detailed and never harsh.

On first listen, I was concerned that the Re0s lacked bass. Some reviews also speak about the bass being a bit thin, but I played around with the different tips provided (5 options!) until I found the right ones. That fixed it and the bass has been beautiful ever since. Coincidentally, this happened after some burn-in time so I can't rule out the benefit of burning these in - the debate rages on!

Design

If there's one negative of the Re0s it's their design from a purely aesthetic perspective. In terms of fit and performance, they're right on the mark, but they look pretty cheap. That doesn't mean they aren't well put together. The bodies are metal and the rubber used in the cable is high quality. The plug is high quality and the insulation is tapered so it'll fit any source you can think of. The cable splits at a classy metal junction and the sliding ring to hold the separate L/R cables together is also metal so it's not like they actually ARE cheap, quite the opposite, but they LOOK cheap.

The phones themselves are simple, black painted metal with touches of polished metal. On the back of the phones is a circular area of bare metal and the finish here looks a bit rough, but it doesn't actually effect the earphones so look past that and be pleased that the Re0s are a sleeper that no-one will be drawn to steal (unless they've listened to a pair ).

Comfort

I'm a novice with canal phones, but I find these comfortable. It's important though that you find the right tips. The Re0s come with S, M & L black rubber tips and S & L twin-flange tips. Play around until you find the right one and pay attention to the bass quality. When the bass and sound isolation are best, you've got the best seal.

Something to note here is that pushing canal phones into your ear can create a pressure lock of sorts in the ear canal. Not only can this be uncomfortable, it can also affect the performance of your eardrum and possibly the phone. If you feel pressure, wiggle the earphone until the pressure equalises and then judge the sound and comfort.

Isolation

Again, as a canal phone novice, I have no real comparison, but these block out plenty of noise when I'm on the train or riding my bike so they're good enough for me.

Source Notes

I was concerned when I bought the Re0s that they may not work effectively on my iPod or iPhone without amplification. They do. I love great sound, but I'm realistic about it and don't want to carry around excess equipment. The Re0s are a perfect way to achieve outstanding sound from a simple source like the iPod... BUT... you won't want to use any equaliser adjustments on basic sources (like iPods). Basic sources don't have the amplification circuits to really handle any tweaking of the sound.

Before I got the fit of the Re0s right I was playing around with the bass boost on the iPod and I forgot to switch it off. Later in the week I was disturbed to hear all sorts of sound quality issues from my iPod and actually thought the amplifier circuit was giving up the ghost (it's an old pod). I suddenly realised my mistake and switched off the bass boost - perfect!

The Re0s WILL show up any poor recordings and sources, but the good news is that their magnificently balanced sound means that you shouldn't have to apply modifications to the sound - just enjoy it as the artists intended.

Overall

These phones have everything right where it matters. They've outperformed everything I've listened to, even phones worth more $$$. They don't look flashy, but they sound spectacular (if you get the fit right). I'd recommend these to anyone.

Pleased by the sound quality, almost perfect with Mini3. After three months I had to return it back, bad contact inside right driver I think. The cable is really tiny. Hope I'll see it soon in better condition.

I really enjoyed the RE0 for a while, but the sound was lacking bass. This happened if  it was not driven properly out of the uDac or any other amp. Straight out of the iPod, there was something 'off' and it wasn't natural. The RE0 doesn't go particularly low.

On the other hand, the highs are excellent. So are the mids. 

For the current price, they are a must-have.

I have rate these a half star for audio quality because they do not play sound anymore. There is a growing number of people who have experienced the terrible quality of these headphones. All of us have experienced the same: after a relatively short period one channel stops working. This is well documented in treads here on head-fi and on amazon.com that sells these headphones. As of this moment, the RE0's are rated #8 in the reviews. These phenomenal ratings reflect the fact that the RE0's sound fantastic when they work, however, this is not the full story. Buyers should BEWARE of the crap quality of these headphones.

I have been using the Head Direct Reo for over a year with my various Sansa MP3's and classic iPod.  These in ear headphones replaced a pair of Etymotic Research 6i's.  Compared to the 6i's the Reo's are a much more neutral, cleaner sounding and comfortable headphone.  They're well constructed and can put up with a fair amount of abuse.

I haven't tried all the >$100 in ear headphones, but these are keepers.

best bang for the buck, nothing else comes close for the price.

This review was written from the perspective of the average user, someone who will buy these for iPod use. I did not use an amp for this review because the average user more than likely won't have one.

Packaging:

Came in a hard plastic case, wasn't a fan of the yellow, but everything necessary came, including various ear tips. Not the best packaging, but it wasn't bad.

Comfort:

Before I had the RE0 I owned the Apple Dual Driver IEMs and various earbuds, even Skullcandy (don't ask why) and compared to them the RE0 ranked one of the worse. The first gripe is the terrible design of the IEM itself, I can't imagine anyone could have though it was a good idea to put ridges on the metal that is in direct contact with the ear. I've heard numerous complaints of irritation caused by the ridges, including myself. A friend suggested to try the double flanged tips. I tried but they were horribly flimsy and the sizes given were either too big, or too small. I generally fit in mediums, so I found this weird. I resorted to the basic tips. After fighting to get a decent seal, irritating my ear in the process, they were finally in and secure, though they were the least comfortable IEM I had ever had in, yes worse than Skullcandy.

Design:

The ridges make another appearance here. I want to reiterate, who thought the ridges would be a good idea? The cables were as thin and frail feeling as the Skullcandy's I had used in the past, which definitely isn't a good sign. The Apple Dual Driver IEMs cable certainly felt much sturdier.

Sound:

This is where the RE0 get the most praise, and I admit, they do sound pretty good. They sound was reminiscent of my Ad700, but for some reason not as fun to listen to. These are very cold sounding headphones, analytical if you will, in my opinion. I can't say I had fun listening to any genre on these, though, and I repeat, they do sound good.

The mids and highs were clear. There is no disputing this. For the price I think they may be the cleanest sounding IEMs in this department. The lows were very unimpressive. You could certainly hear them, but there was no feeling to them. The extension on them was non-existent. The bass was punchy, but very thin. 

The soundstage was pretty decent for an IEM of their price I must say, probably the best in this price bracket. No complaints here.

Isolation was nothing special here. I could hear my surroundings alright with no music playing. Microponics aren't  too bad compared to others.

Overall the headphones left me with an analytical feeling. I felt like I was dissecting each track, which made music listening very boring. These are also not good for varied genres, anything with distortion or heavy bass was unlistenable for me, the RE0 simply sucked all of the life out of them. They didn't really shine with any genre, but clean music sounded alright on them.

Value:

For the price these are not bad, but they are blindly recommended over much better choices. There are far more comfortable IEMs with a better build feel to them for under $100. Sadly though those IEMs MSRP for ~$100, these retailed for $250 at launch. For $79 I think they are fairly priced, but certainly don't deserve the praise they receive in my opinion.

Please keep in mind my ratings are in comparison to similarly priced IEMs, not $1,000 IEMs.

I got these in a parcel on the 13th after reading the reviews on Head Fi and elsewhere - (nearly all comparing them very favorably to much pricier options). The left headphone fell apart within one week of usage. Still waiting to hear back from the seller to see if I can source a new pair. So I'm back to using my Audéo PFE 112's for now... (no bad thing).

Bear in mind that I've only owned these for a week so far.

Sound Quality

The sound quality Is great for something in this price-range. This has already been said many times before so I won't go into too much depth, but the mid to high end is VERY detailed. They lack warmth and come across as very analytical IEM's quite similar to a pair of Etymotic ER-4P's, but  if possible, more detail in the mids - however, I'm no basshead but I found them overly cold/flat. I was forced to tweak the EQ.

After browsing head-fi I tried removing the filters and foam from within the body. This served to make them overly sharp at the high end and found that replacing the filters but leaving the foam out helped reign them in. I found using foam TX400's also helps with the bass (even though seal is inferior to the silicone caps). I believe this really helped the sound and makes them slightly warmer.

The sound-stage is impressive and very wide open. These are great (after modding - much much better) to listen to Classical and Jazz, even classic/proggy stuff - hammond organs really shine. Brass is awesome - I tested with:

1. King Curtis (Live at Filmore West) - Memphis Soul Stew(ALAC)
2. Charles Mingus (Let My Children Hear the Music) - Adagio ma Non Troppo (ALAC)
3. Dmitri Shostakovich - String Quartet No. 15 in E-Flat Minor Op. 144 (1974) II- Serenade (Adagio) (FLAC)

All of the above sounded great. Crystal clear and wonderful clear separation between instruments and vocals nice fast attack. The funk was somewhat removed from King Curtis though... and similarly in other more bass heavy tracks.

Bass is detailed, not nearly as terrible as indicated in some of the reviews I've read it does seem lifeless - I found this depends heavily on the seal you get with which tips you choose.... I ran these through several amps. I used them on my imac through a mini 3 at home - this added a bit of warmth and helped out the bass. When on the move I found the E5 is a good (cheap) option to add a bit more drive - foam tips helped the bass here - however, I think they would benefit from a nicer amp.

Build/Comfort

I initially used the double flange silicon tips (which are huge) - these isolate exceptionally well, but after switching to the TX400 foam tips, I'm not going back.

I have to mention that these fell apart on me after 1 week. The left ear has also started to crackle in more bass heavy notes, but I blame dodgy E5 amplification for that - they were fine on my home amp.

Even with the quality of sound - if any headphone falls apart after a week of use I'm afraid it's a write-off. I could just be unlucky though as others don't seem to have had the same bad luck.

To be fair - it's just a superglue fix, but if I was out on the move and this happened, then it potentially could have ended up with the wires pulled out or worse. So far these have the worst build quality of any headphone I have ever owned - the cables have a weird memory to them (and they are kind of crappy cables at this price) - the newer version which I have has a banana shaped jack.

Overview

After playing with them and hearing the sound change (positively - I'm sure they got a touch warmer) after a week of  burning in and constant wear - I'm in agreement that these are a nice set of IEM's. If you get a 'good pair' and they don't fall apart on you, then great. However, I think they seem to be getting too much praise for what they offer. I'm certainly glad I didn't pay the full launch price for them.

I for one will be sticking with my PFE's for a while - they are far superior IEM's for very little more in price and it's preference I'm sure, but they seem to have a nicer quality and mellower bass. I'm honestly hoping for a full refund rather than a replacement set - but they'll make a nice backup pair if I get a replacement.

I really like the sound of this buds but the right channel stopped working after just one month without any reason. I think it's the same problem, others also described in the forum. I emailed Head-direct and asked hem what to do. Since I thought it was a cable break in the right ear itself, I openend it (to fix itt myself). After seeing that was not the issue I hoped they still want to take a look at it. After a good and friendly conversation by email I'm added to the replace warranty plan. Even after saying I opened them by myself (normally the warranty voids). I really appreciate the service they give. Now awaiting the replacement to write a review.

This is the second time within a year these have developed a fault in the cables. This time it is in the mini jack connector, last time it was near the left earpiece. Needless to say I will not be returning these for a new pair that can develop another fault in the cable. This is unforgivable really. 

The housings are unnecessary heavy, and the supplied single flanged tips don't fit my ears well at all, the biflanges work somewhat but slips off the phones all the time.

The sound is pleasant, balanced and suits me fine, if I had a working pair I'd be listening to them now.

I don't know what to go for next time, but it will certainly never be from this crappy manufacturer.

Average comfort, amazing value. Sound that belongs to 200$ range.

You don't need another review about how good these sound. But I had two pairs, both of which lasted only a couple of months before one ear went dead. I was keeping them wrapped around my ipod in my bag but wasn't abusing them. So either I had shocking luck or these phones are a bit fragile.

There's so much said about these.

I was positively enamoured with my Etymotic ER4Ps. I still am.

But I picked up a pair of RE0s cheapish. And sold my ER4Ps because these were half the price and almost as good.

The RE0s are smooth, clear, fast.

The only knocks against them are:

1) the fit of the different tips. They aren't as good in isolating sound as the tri-flange on the Etys. Also, I haven't found a perfect fit with any of them. And some are a real pain to put on.

2) The cable is really thin and feels fragile. I can imagine they wouldn't last if they got caught on something and yanked.

Otherwise, price-perfomance ratio puts these way ahead of single-driver designed IEMs.

In short: I love these headphones; they are an incredible value and all head-fiers should pick a pair up. While they are not as "fun" as my Grado cans or Fischer Audio IEM's, the RE0 has a neutral sound and can easily distinguish between instruments. Cymbals and acoustic guitar sound lifelike and while the bass impact may be below average, the accuracy of the lows on the RE0 have me preferring them to the lows on my bass-centric Fischer Audio Eterna.

These are an incredible value at 79.99 and everyone should at least consider them for their next IEM purchase.

I will just say that they are a bargain for a such price

Housings are made of metal and are solid but the cloth version of the cable is prone to microphonics.  The jack is fairly weak and the strain reliefs aren't particularly effective.  Fit is easy as the earpieces are fairly small and isolation is just above average.

Sound is excellent for the money.  Treble is more prominent than in most earphones but is never harsh and has better extension than anything I've heard, detail is excellent.  The midrange is natural sounding with little colouration and is also very detailed.  The RE-0 is light on the bass but extends fairly low with excellent speed and punch but little weight behind it. 

Amplification helps improve the bass quantity, punch and speed some more and overall dynamics are improved.  They sound a little sterile without an amp but do not need one, they just scale well with the added power. 

Overall sound is airy and slightly warm and suitable for a wide variety of genres but not anything bass heavy.  They are very revealing and detailed but not agressive with the detail and are quite relaxed sounding.  Transparency is excellent and the individual characteristics of the recording really shows.

Great IEM for it's price. Produces a very detailed, transparent sound. Not for the basshead but personally I think the bass is just adequate, not too overwhelming. I just love these phones

I have bought RE-0 when I was looking for some portable headphones, but didn't want anything bigger than in-ear ones. I have searched for more expensive ones when I came to RE-0. The price was 99 USD, which was less that I planned to pay. Reviews were highly positive.Since I don't travel much, for me it looked like a good value for money.

Overall quality is very good. Soundwise, they are very detailed, perhaps too much ;-) I can hear things I have never heard before. Take it as you wish, I mean it in good way... Some might miss that familiar boomy bass. RE-0 bass is definitely present, but very tight, precise and clear. I don't mind that "flaw" (if you want to call it this way). Acctually with most songs I prefer it.

Design is OK, everything you can expect from headphones price at 79 USD (as I write it).

Comfort - RE-0 come with plenty of tips, I would suggest clear bi-flanges.

Isolation is just average, sufficient in most cases, but expect some noise, especially in very noisy enviroments (transportation)

I was quick decision for me. For the price, I would recommend it to everyone who seeks excellent, detailed sound for a very reasonable amount of money. The only disadvantage might be that tight bass.

I was lucky and grabbed these from another head-fier for $40.  I've owned many IEM's during my head-fi roller coaster ride.  I believe the only top tier universal IEM's I have not had the pleasure of owning is the UE triplefi10 and Ortofon E-Q7.  Throw the RE0 in the mix and is clear, I mean clear that this $79 retail IEM can play with the best in most areas and exceeds in others. 

Similar to the review, if you're a basshead, stay far away from these.  However, if you fancied the Phonak PFE and was wowed by their clarity and detail, the RE0 brings up a few notches.  Detail freaks, buy these now, run and cherish them.  I rank them higher over the ER4S I use to own mainly because I never could get use to them jammed so far in my ear.  If you want bass and similar clear details look at the JVC-FX700.

Build quality is good.  From afar, they look very average and almost on the verge of cheap, but looks can be deceiving.  You have to hear the truth these magical IEM produce.  They deserve all the praise and accolades even at their once retail price of around $200.  I just love listening to my Pink Floyd tracks in FLAC and hear more details than before, it almost feels like magic.

Even at their current price of $79, like many claims before, the are no doubt a STEAL.  And yes, they benefit greatly being amped. 

If you haven't tried these, you need to.  It's hard to believe they are dynamic drivers versus highest quality BA.

Too lazy.  Will write later.

The are SO many things the RE0 does amazing well.  Treble extension is crazy without any graininess or fatique.  Bass extension is also very low, but the bass body is probably too polite.  The bass decays too quickly to give a sense of bass warmth and body, and the bass impact is too tame. 

But this bass response is from the RE0 unamped.  Suprisingly, a simple little $25 Fiio E5 with it's bass boost really improves the RE0 -- even more so than my $120 iBasso T3 (no bass boost on it).  The E5 gives a slight bass boost and a very slight treble cut (to help the sense of the bass boost) -- but the treble cut does no harm at all to the awesomeness of the treble response, extension and smoothness.

The one thing the RE0 does lack is a sense of space around instruments.  It's not that it gets jumbled in busy music passages -- the instrument layering is just a bit 2-dimensional, a bit flat.  But that's a technical aspect that many people won't recognize nor be bothered by.  It doesn't prevent me from enjoying the RE0.

Its very clean sounding In-Ears.

I am not a person requiring huge amounts of BASS but the BASS on RE0 is slightly less than I would have liked i to be...Having said that I find BASS to be quite Tight. 

Sound Stage is average.. Instrument Seperation is quite good.

With the Amp, for which I paid a small extra,.. it sounds even better.

The White Bi-Flanges are perfect for my ears.

Am able to have them for prolonged times.

First pair quit working (left channel) in six months. The replacement lasted 4 months and died a similar death. I don't go anywhere with them and they were used primarily at home and treated with care. I didn't bother any further follow-up. Sound was impressive. I liked these a lot and sorry they're rather disposable.

I've searched a bit to find a few cans that work with my lifestyle.  Portability is important to me so that rules out lots of great products.  I like that the RE0 is low profile, not attracting any attention.  The RE0 may be a perfect compromise between sound quality and price.   More expensive buds may be more articulate or image spectacularly, but it would be crushing to break or loose them in my day to day roaming around. If these cans sin it is only of omission.  To my ears they are quite musical.

I have numerous pairs of Apple's earbuds and I keep a pair in my briefcase, my gym bag and locker, etc, but they leave me longing in two ways.  I want more out of the sound because I know it's possible and I want better isolation.  The RE0 is a bigger improvement in sound than the price might suggest.  If I have a nit to pick it's that I'd like better isolation.  Clearly that is subjective and the RE0's come with multiple ends to try.  May be some day feeling flush I will pull the trigger on a pair of customs, but until then these work very well.

I purchased RE0 after a lot of thought and research here in head-fi forums. At first I was puzzled by their sound. Having used only Sennheiser CX 300 before I found the sound to be too complex and the highs too pronounced. I had them playing virtually all day long (and night) for the first 3-4 days to burn them in as I knew that they require a long 150+ hours. I was also using them while burning them in to experience the differneces in the sound. The most notable difference was the bass, that really became more tight and clear. Bear in mind that I got used to such a sound signature about one, one and a half week after regular listening with them. Now the clarity is amazing, the highs are jaw-dropping, mids come clean and not overshadowed by bass and speed is up to par with fast paced songs. I tried listening to CX300 the other day, 1 month after I got the RE0. Couldn't get past 2 minutes, too much bloated bass it sounded like there was a cannon firing next to the band. I can't believe that I heard music before them. The few thing that bother me are the lack of bass body, since I am not using an amp (for now) and my source is a sansa clip+ and the fact that wearing them over the ear can be a bit bothersome and uncomfortable. Another issue it that they are very source revealing, so if you have low bitrate mp3 files, prepare for a big dissapointment as they will sound worse. All things considered, best purchase so far for me, and I am sure as time goes by I will just appreciate them more, and so will you.

I've had these areound for a while and absolutely love them, IMO its the best $100 a headphone freak can spend. I was really happy with the bass response and they're practically weightless. 

I really wish the RE0s lived up to their promise.  They do sound really good, but they are clearly the product of cost-cutting.  I bought a pair, and within a month, one of the buds was cutting out, and soon there after failed completely.  I had them RMA'd, and within 6 months, the replacements began to fail (the adhesive that keeps the speaker part glued in to the casing is failing or has failed on both buds).  I would have paid 50% more for these headphones and been happy if they stayed in one piece, but now, I wouldn't be happy if they had cost 50% of what I paid.

tl;dr great headphones crippled by terrible materials and quality control.

"They may disappoint bass-heads, but for anyone who strives for true audio reproduction, this is the IEM for you. "

I'm not a bass head, but I don't hear true audio reproduction.

Yes the bass response goes down low, evident in a song like  Nick Cave Red Right Hand, where the almost sub-bass frequencies (<50Hz) are clear. But I do perceive a slight dip around 50-100Hz. So in an acoustic track the double bass can be hard to hear, in a rock track the kick drum lacks punch, the bass guitar lacks depth. It's only slight, the rest of the spectrum sounds beautiful, but the EQ down low does not sound flat to me. That's out of the box tested on iPod nano first gen, iPod 5th gen, ipod 4th gen and iPhone 4s.

Added note: I've started using these with the rubber tips from my Ultimate Ears and it improves the bass response slightly. I think the rubber tips on the RE0s are too hard and it's hard to get a good airtight seal. 

Well I searched and searched everywhere I could to find a replacement for my Shure E2c's and with a little skepticism I went with the HiFi Re0s. I couldn't wait to try them out. I didn't really believe in the burn in time for buds but to my dismay these needed a few hours to really get the full body sound. I also had to replace the rubber tips with Comply foam from my local Radio Shack for a mere $15. So total I have spent $99 on these and I am happy to say I will be looking to purchase these again when need be. I was really worried I wouldn't find what I came to really enjoy from my E2c's. The E2c's had great bass and great sound isolation. The Re0 have a more full natural sound for less money. So i rated the value high but the isolation low because of what the E2c's provided. Comfort is only 3.5 because of having to go out and purchase after market tips. They are now stellar and fit better then my E2c's did, which I thought could never happen. Audio quality is only a 4 because I know there are better buds but for more money. The design is small and compact and so far seem durable, but the only worry is the cord is your basic quality. These are very affordable even for the average listener. These come highly recommended from me but who am I?

I had the Re0 since Late Feb and I  love it! I was hunting for a bargain at first and when I received mine I was like"meh" then after 50 hours the bass starts to kick in and mids is much warmer now after 200 hrs I ditched my full can(srh840) and removed the filter, much more sharper  but that is just me. I would highly recommend this to anyone who is looking for the best item under $100 and if you dont like the original tips try the sony hybrid tips($10 at sonystyle). 

Congratulation on the success and a big THANK YOU to HiFiMan for this exceptional earphone and I do suggest a less microphonic cable and maybe offer a wider color selection (Sorry I am baked :)