Performance

HiFiMAN's gamble on making a dual-purpose headphone has paid off. The Edition S sounds great when in open-back mode and acceptable in closed-back mode. To fully understand the challenge, try to cover the grills on pretty much any set of open-back designed headphones and witness the havoc it does to the frequency response.

The Edition S is of course also affected when you give it a rear cavity. First of all, the bass gets duller and the midrange gets tinier. Also, the upper midrange gets quite a few more dips and bumps, which detracts quite a bit from the overall presentation. What you gain when you put the covers on is that the headphones no longer leak, which is great if you want to listen to embarrassing music in public, and you gain around 1-2 dB of noise attenuation, which helps if you plan to listen to music in a noisy environment.

Sibilance is not a problem with this headphone as even pretty harsh recordings are listenable. The upper midrange could sometimes do with a little presence for strings and crunch guitar, but that would make them a bit more fatiguing to listen to if you listen to a lot of different genres.

Once playing in free air, you really do get to hear HiFiMAN's new dynamic driver in action. The bass extends well and has a great amount of punch and presence. Detail also keeps up with that of a lot more expensive headphones in the bass and midrange department, but the treble seems less controlled than on the Sennheiser HD-650 powered by a decent amplifier. The Edition S can be powered straight out of a decent phone or DAP and does scale a little when you hook it up to the O2 or a similar amplifier, though the differences are marginal. The treble extends fairly well, but is not as detailed nor as flat as what you get from other fully sized $250 open-back headphones.

The tuning of the Edition S is a little different from what I am used to hearing from HiFiMAN. There is a substantial 60-80 Hz bump which brings the bass forward and gives it a little more omph compared to a flatter bass response. While the upper bass is substantial, it does not completely overpower the midrange; however, these headphones are best described as more bass than midrange focused, which makes them stand out in terms of tuning in the HiFiMAN range.

The soundstage is good for a set of portable headphones, but cannot begin to compete with larger open-back headphones. It is cohesive, but far from as spacious when compared to the higher-end HiFiMANs, or the HD-650 for that matter.