Over the last week or so of listening to the RE0s with a wide variety of music, I’ve grown accustomed to its unique sound signature because they are so unlike all of the various headphones/earbuds/IEMs I’ve listened to so far. Everything I’ve listened to prior to the RE0s has colored the music I’ve listened to with its own sound signature. From the cold, analytical presentation of my HD280 Pros to the deep, bloated bass of my V-Moda Bass-Freq earbuds, everything layers a bit of itself over the music. With the RE0s, there’s nothing there. The sound signature is entirely flat and while that may sound like a negative, trust me, it isn’t. This neutrality creates total transparency and allows the source to come through exactly as the artist intended it to. Because of this, the RE0s are unquestionably the best headphones I’ve ever heard.

The beauty of the RE0s is that they don’t color the music coming through them. There are no peaks and valleys in the presentation and it’s entirely smooth, creating a very enjoyable listening experience. Some headphones can cause fatigue after long periods of listening, which prompts a break. Even some of the best headphones out there can cause this “listening fatigue” but with the RE0s, this hasn’t been an issue for me because they’re so well balanced.

When I wrote my first impressions of the RE0s a short while ago after listening to only a couple of songs, I remarked (on my GameSpot blog) that the treble was a bit harsh on the upper end. Now, after breaking them in for a while, they’ve settled into their final sound signature. Treble sparkles nicely in the high end without being strident. Chimes and xylophones sound wonderful and slightly warm on the RE0s which I greatly enjoy.

I originally thought that the bass and low end in general was lacking at first, missing a certain fullness and impact, but it has grown stronger and is now very pleasing, even to the bass-head in me. What I’ve noticed about the bass though is that it is lacking a bit in terms of body. See, the bass hits and extends pretty deep into the low end, only rolling off at the lowest frequencies and just like that (imagine I snapped my fingers here), it’s gone. It’s tight and quick, almost to a fault, but its presence is enough to be heard and, most importantly, felt.

The RE0s improve in terms of bass response and warmth when paired with a Fiio E5 portable headphone amp. The bass boost feature adds some body and weight to the bass as well as a hint of warmth to the RE0’s sonic presentation. For me and my tastes in music, this is a plus, but without the bass boost feature or even using them un-amped entirely, the RE0s are more than satisfactory.

It’s worth mentioning that microphonics can be an issue with the RE0s. If you’re unaware, the word “microphonics” in the case of IEMs is a phenomenon that occurs when vibrations (usually external) are transmitted through the earbud itself and into your ears. For instance, if you tap the cable with your finger while the IEMs are in your ears, those vibrations will likely be heard in your ears. With the RE0s, practically every external force can be transmitted through the cable and into your ears, be it the cable brushing against your clothing or simply waving in the wind. While this isn’t much of a problem if you’re, for example, sitting at home listening to music on your laptop since you probably won’t be moving much but when on the move, unless the cable remains very close to your body and doesn’t move much, regular movements like walking can create microphonic noise. This noise can be very loud and distracting at times when you’re trying to get immersed in music but for me, while it’s certainly annoying at times, it’s far from a deal breaker. To combat this, Head-Direct includes a shirt clip which helps to deaden cable vibration noise before it’s transmitted to your ears. Wearing the headphones over the top of your ears (as opposed to dangling down from them) also helps with microphonic noise.

I’m a novice when it comes to reviewing headphones so it’s worth taking everything I’ve said here with a grain of salt. I don’t have a ton of reference hardware that I can really compare these to in terms of sound quality except my full-size HD280 Pro cans, the V-Moda Vibes I received recently and my outgoing V-Moda Bass-Freq earbuds. One thing I do know is that I can recognize high quality headphones when I hear them and even though I haven’t heard much audiophile-grade equipment, I can tell that the RE0s are in the upper echelon. I describe myself as an audiophile on a budget so as much as I would love to listen to a pair of Sennheiser HD800s paired with a high quality CD player (or maybe a fifth-generation iPod that’s received the “iMod” treatment) my budget is not going to permit me to do that. But for $84 shipped from Head-Direct (at the time of this writing), I am very pleased with my purchase.

In terms of bang for your buck performance, the RE0s are perhaps the best deal in portable headphones/earbuds you can get and I find it hard to believe that anyone could be disappointed with them. Overall, sound quality is simply superb, exhibiting a decent soundstage, thoroughly natural and exceptionally clear sound that isn’t lacking in any area. The design, while a bit derivative of the V-Moda Vibes feels sturdy without being heavy in your ears. I really can’t recommend these highly enough. They’re absolutely fantastic and if you’re looking for some great sounding portable headphones for on the go and home listening, you’d be quite remiss in overlooking these.