PerformanceHiFiMAN HE-400s are so far the cheapest way to get into higher end planar magnetic headphones. The HE-400's modest amplification requirements and relatively low price compared to the HE-500s makes them an ideal choice for music aficionados on a semi extravagant budget.
Before the listening tests were carried out, the headphones were burned in for well over 100 hours. We did have a sneak peek into what the HE-400s could do right away and the sound signature did not change noticeably over the 100 hours, which is not unusual for planar magnetic (iso/orthodynamic) headphones.
The HE-400s ship with the new pleather ear pads from HiFiMAN which are slightly stiffer and a little deeper than the original velour ones. There are some subtle changes to the tonality of the headphones depending on which ear pads you have on. The pleather seems to add warmth and add a little to the bass experience, but do not expect a night and day difference between the two sonically. Comfort wise the velour pads are better in the long run and for anyone situated in a warm country you should definitely consider getting a set of velour pads.
Sound signature wise the HE-400s take on from the HE-500s and are a long departure from the HE-300s which we quite liked. The HE-400s possess a warm, laid back midrange compared to the somewhat treble happy and definitely more edgy HE-300s.
Even compared to the HE-500s and Sennheiser HD-650s the HE-400s are darker, and their sound stage gives you the perception of being further from the music. The sound stage coherency is still very good albeit more left right than what you get from a set of Sennheiser HD-800s, HD-650s or AKG K701s for that matter.
Despite featuring a smaller driver with a simpler and smaller magnet array, the HE-400s do a remarkable job at keeping up with the much more expensive HE-500s which is one of the most detailed we have come across over the past two years.
Bass wise the HE-400s edge closer to its bigger brethren and manages to pull off an equally appetizing low end albeit lacking the last touch of details that made the HE-500s so exquisite. Compared to headphones such as the HD-650s the HE-400s have a faster bass with more presence. The low end is incredibly powerful and snappy, it is not quite as linear as the HD-650's or the HE-500's for that matter, but it is very close.
One small issue with the HE-400s is the treble, or to be exact the lack thereof. The high end is not completely omitted, but do not expect any form of sparkle or artificial airiness. The upper midrange does blend in perfectly with the high end which means they are very easy on the ears even for longer listening sessions. With sibilant recordings you do of course get a little too much emphasis on the Ss, but any normal recording will sound just fine.
For a normal high quality headphone system the HiFiMAN HE-400s seem a logical place to start, they have one of the best low ends around and a midrange that despite its slightly lower detail level than the HE-500s is still among the best in class, even outperforming the more expensive Sennheiser HD-650s. Compared to Fostex T50RP orthodynamic headphones the HE-400s are in a completely different class, the sound signature is much more pleasing with a much fuller low end, and a higher general detail level. The difference in detail level coming from the HD-650s or T50RPs for that matter is clearly audible on well mastered tracks. They just provide the next level of layering and precision compared to the other two.