Ultrasone HFI-680 Headphones with S-Logic - Product Review

The Ultrasone HFI-680 headphones offer an excellent full-size alternative to both in-the-ear and other types of full-size headphones. The unique driver design sends sound to the out-ear structure rather than pushing sound directly to the middle and inner ear. By using this more indirect approach, the sound more naturally mimics the way sound is delivered to the structures of the ear, such as when listening to loudspeakers. Also, besides sounding good, the earpads are comfortable to wear for long periods of time. The Ultrasone HFI-680 is worth a listen. After reading this review, check out my HFI-680 Photo Gallery

What makes the Ultrasone HFI-680 different from many headphones is the incorporation of S-Logic. The key to S-Logic is the position of the headphone speaker driver. The driver not located in the center of the earpad, where it would send sound directly to your ear, but slightly off-center within the earpad (see photo). For a comparison between the driver placement of the Ultrasone HFI-680 and more traditional headphones, check out how the driver is placed in the KOSS Pro4AAA Headphones.

By placing the driver in an off-center position, the sound is sent to the outer ear structure first, where it is then funneled into the middle and inner ear in a more natural fashion. In other words, the sound is heard as it would be in nature or when listening to speakers; the sound reaches the the outer ear first and is then sent into the middle and inner ear.

I found that this approach seemed to work very well. Frequency response across the board (lows, mids, and highs) was excellent. In addition, there was an increased expansiveness and directional perception of the soundstage. Instead of the sound just coming at your from left and right, the soundstage opened up to the beyond the earpad borders. Sound appeared to originate from slightly above and slightly behind my ears as as well as slightly from the front. With music, voice and instrument placement was very precise and distinct. Of course, the degree of this effect also depends on the source material being played.

In addition, lower frequencies were very tight, not boomy, when compared to the Koss 4AAA full-size headphones, and not dropped off when compared to the Shure E3c compact stereo earphones that I used for reference. The Ultrasone HFI-680 did very well with challenging music tracks, such Medeski, Martin, and Wood's Uninvisible, Heart's Magic Man, and Pink Floyd's Dark Side of the Moon. Also, experiencing DVD and Blu-ray Disc soundtracks was also a pleasing experience with the Ultrasone HFI-680.

Although it is not the same experience listening to DVD and Blu-ray surround soundtracks with the Ultrasone HFI-680 as it is when listening to an actual 5.1 or 7.1 loudspeaker setup (rear sound effects are minimal), it is still a credible experience. One drawback is that the center channel is not placed at quite enough distance forward; it is more in the center of, and slightly above, your head. On the other hand, the left, right, and surround effects have enough spaciousness and direction.

Ultrasone has taken an innovative, yet simple, approach to headphone listening that is well suited for listening to either music CD or DVD/Blu-ray soundtrack material. The HFI-680 is definitely worth your consideration.

Components used in this review:

Headphones used for comparison: Koss Pro4AAA Headphones, Shure E3c Sound Isolating Stereo Earphones.

Home Theater Receiver: Onkyo TX-SR705.

CD Player: Denon DCM-370 CD Player.

DVD Player: OPPO DV-980H Upscaling DVD Player.

Blu-ray Disc Player: Sony BDP-S350.

Disclosure: Review samples were provided by the manufacturer. For more information, please see our Ethics Policy.