Ultrasone make some bold claims with the HFI-680 headphones, promising the sound isolation of close-back cans with the "honest sound" of open ones. Given that it can be hard enough creating something pleasing in just one of those categories, have the headphone specialists bitten off more than they can deliver? SlashGear hit shuffle and set to finding out.
When it comes to packaging, Ultrasone could perhaps learn a few things from Monster Cables. It's subjective, but we don't think the HFI-680 box does justice to a $230 purchase. Giving it its due, though, it's sturdy (and large) and delivers on its primary purpose: protecting the Ultrasone's in transit. Inside, there're the headphones themselves, a carrying bag, 1/8-inch to 1/4-inch gold-plated adapter and a demo CD, together with the printed instruction manual.
First impressions of the HFI-680's are good. Build quality is excellent, and while the construction is primarily plastic it's all sturdy and thick. Ultrasone may not have Monster Cables' packaging, but they obviously studied at the same school of branding: the headphones are littered with logos, from the huge "Ultrasone" banner picked out in white across the black headband, to the various graphics and text on the metal-effect ear cups.
The headband itself has a tenacious grip, and should we ever be mugged wearing the HFI-680's then we'd worry our head would get yanked off with them. There's plenty of adjustment in other directions, though, with smooth-sliding length travel and ear cups that can both tilt and swivel. This allows the Ultrasone's to be furled up into a relatively tight bundle and transported.
Rather than exiting from both ear cups, the cable snakes up through the headband from the right and hangs only from the left. At around 3m it's easily long enough to reach into a bag or tucked-away pocket, and there are some seriously over-engineered stress relief protectors at both the headphone and the plug ends. The normal 1/8-inch jack is fixed and gold-plated, and has screw knurling for the supplied 1/4-inch adapter. We much prefer this over the regular push-fit adapters.
With a little run-in, the Ultrasone's didn't disappoint in their sound performance. Despite the size, given their 75 Ohm impedance they can be driven by most PMPs. Where they shine, however, is when used with a proper amplifier. This can either be in a home hifi setup, or with a separate portable PMP amp. Suitably equipped, trebles are sparkly and engaging while bass errs just on the side of friendly. Unlike the Monster Cables Beats by Dr. Dre, which place huge emphasis on the low-end frequencies (much to the satisfaction of R'n'B and hip hop music), the HFI-680's are broader in their appeal. Mid-range frequencies are still underserved in comparison to the extremes, but there's still broadness to the sound stage that belies their closed-back build.
If we were to try to pigeon-hole musical styles best suited to the Ultrasone's, we'd probably lean away from classical merely because of their relatively underserved mid-range. It's certainly no deal-breaker, but there's a tendency for the mids to lose detail compared to the rest of the frequency range. Used without a separate amplifier this is less noticeable, but only because you lose the top and bottom sparkle that makes the HFI-680's so engaging.
Nonetheless, we like the Ultrasone HFI-680's, a little more perhaps than we do the Monster Cables Beats. That's testimony to their increased flexibility; obviously your own mileage may vary depending on your musical tastes. What we'd really like to see is a version with an integrated amplifier; we've a feeling that most buyers looking at the Ultrasones for PMP use won't pair them with a portable amp, and as such will never experience their full potential. A built-in amp, preferably switchable in case a third-party one is preferred, would give a more accurate first-impression of the HFI-680's charms.
At $230, these aren't cheap headphones. Still, they're well made and sound great, and neat touches such as the foldable design; well thought-out jack adapter and flexible adjustment stand them in good stead. If you're willing to pair them with a suitable amp, they'd make an excellent choice.