Perhaps the best closed headphones available.

I have friends who would never consider buying a set of headphones which cost more than $200, but the HFI 700s are actually quite a bargain at less than $250 (as priced at many on-line dealers.) My purchase was made more out of desperation than on the basis of product reviews, as I desperately needed a more comfortable pair of closed headphones for listening in noisy environments. Fortunately, it was a good decision. These are by far the best sealed headphones I've ever owned.

In absolute terms, I still prefer the sound of the Grado SR325is and the Sony MDR-SA3000s over the HFI 700s, but the former are both open headphones and even the sound of air conditioning is a distraction when you want to do some serious listening.

Most closed headphones are either uncomfortable or have poor tonal balance. Closed headphones also tend to do poorly in imaging sound sources. The HFI 700s actually shine in these areas. They are extremely comfortable (though not as comfortable as the better open headphones) and have a really nice sound field. The mids and highs are clear without being overly bright. The sound isolation is very good as well, nearly on a par with many professional DJ headphones.

There are, of course, some negatives.

First, they need more power than the average portable media player can provide. You can't really do them justice without a separate headphone (portable) amplifier. On the road, I use either a Practical Devices XM4 or a C&C XO with great results. At home,I use a Little Dot II++ tube amplifier.

Second, they have a coiled cord. This is just plain wrong...I'll never understand the logic behind coiled cords on headphones intended for serious home or portable use. The LAST thing I want is for my cord to be "springy." Manufacturers should just make the cord a convenient length (maybe 48" to 72") and let you use an extension if you need it. With that said, the cord does seem to be more durable than most.

Third, the construction of the headband seems a bit cheap, or at least poorly-executed. The trim pieces are pretty delicate, even if the cables aren't. UPDATED 10 September 2007: The trim pieces at each end of the headband come off VERY easily. In fact, mine pop off when I pick the headphones up by one earcup. The plastic piece is supposed to slide up and interlock with three tabs, but these tabs apparently don't hold very well. What's worse, the connections for the headphone conductors are completely exposed when the trim piece comes off. I've had to resort to placing a small piece of duct tape on each piece to keep it from sliding off.

In summary, this is a great choice if you (1) want a great-sounding, comfortable, sealed headphone, and (2) are willing to spend more than $200. Nothing else in this range will touch it. (The HFI 700s beat the pants off the Sennhesier HD-280s, for example.) Just be sure you save some $$$ for a nice headphone amp.

UPDATE: Not really an update, but a couple additional comments. The "S-Logic" feature of this headphone is actually just a function of the positioning of the transducers in the earpieces and the configuration of the transducer chamber. This definitely improves the imaging of the headphones. With many headphones, I end up pushing the headband back on my head so the transducers are more forward of my ear, improving the sound field image. This is not necessary with the HFI 700s.

Finally, let me emphasize again that, in my experience, closed headphones usually aren't able to match the performance of open headphones. (Just take a look at the most expensive and most highly-rated headphones and you'll see that they are virtually all closed designs.) The HFI 700s have exceptional sound for closed headphones, which is why they impress me so much. But they earn only four stars because they are up against extremely tough competition in similarly-priced open headphones.

UPDATE REDUX: I'm a bit puzzled, because a friend of mine just got a set of HFI 700s and they DON'T have a coiled cord. Was this a recent change? Do I have a set of 650s that are relabeled? I just don't know. But if you are given the opportunity, check to see that a pair you might be interested in DOESN'T have a coiled cord.