This is a follow up to Playback Editor Chris Marten’s review of the HiFiMAN HE-400 (click here to read the review), HiFiMAN’s groundbreaking low-cost planar magnetic headphone that debuted this year at CES. I remember the first time I sat down and listened to the original version of the HE-400 and how shocked I was at the dark, moody tone it produced, especially in relation to the top tier planar magnetic headphones that HiFiMAN manufactures. I also remember noticing how truly easy the HE-400 was to drive and thinking “if only the tonal balance was a little more neutral, I would be a happy camper”…enter the HiFiMAN HE-400 with Revision 2 drivers.
As we understand things, HiFiMAN built only one production batch of the original HE-400s, with many of those units being made available as press samples (our first HE-400 review unit came from this batch). Our review samples of the original HE-400 performed reliably from the outset, but we have learned that other users were not so fortunate because a disproportionately large number of the original HE-400s exhibited premature failures in the field. For obvious reasons this is a problem that immediately caught HiFiMAN’s attention.
Basing its decision partly on a desire to improve long-term HE-400 driver reliability and partly on reviewer feedback on the sound characteristics of the original HE-400s, HiFiMAN moved swiftly and decisively to revise the HE-400’s planar magnetic driver. At the same time, the firm also elected to make several small but important running changes in other areas of the headphone.
Our mission here is to see how (or if) the Revision 2 version of the HE-400 differs from the original, and if so to determine if the changes are beneficial ones.
There will be many references back to the first review of the HE-400 so I would advise that if you haven’t already read the original, full-length review of the HE-400 that you do so now (using the link above).
What’s the big change?
As Chris Martens noted in his review, and as I noted in my first listen of the original version of the HE-400 headphone, one could most definitely hear the lack of upper midrange and treble power and clarity because tracks that had been warm and responsive throughout the entire range in other headphones (such as the HiFiMAN HE-500) suddenly seemed much darker through the original HE-400, and felt like they lacked snap of listening to live music. The most noticeable change when listening through the HE-400s with Rev 2 drivers is a welcome boost in upper midrange and treble energy—a boost that greatly improves the headphone’s overall accuracy and neutrality. Not only do the new drivers help to define the upper register voices of most instruments much more clearly (especially when the instruments play in overlapping pitch ranges), but they also help provide an additional shot of dynamic energy to musical tracks as a whole.
I am a very big fan of both country and bluegrass music and some of my favorite test tracks come from the album Alison Krauss & Union Station – Live [Rounder]. Like many of you, I’ve found that the instruments used to create bluegrass music often play in similar pitch ranges so that the real definition and soul comes from hearing and appreciating subtle differences in timbres and voicing characteristics between the instruments. I felt the original HE-400 revealed musical timbres well over some parts of the audio spectrum (namely, the lower midrange and bass regions), but less well in others (specifically, the upper midrange and treble regions). For example, the original HE-400 had no trouble reproducing the unique thump of the upright bass but often lost definition when both the banjo and Dobro played simultaneously (something which, if you know your bluegrass, happens often). With the Rev 2 drivers in the play, the HE-400 sound much more clearly defined on simultaneous banjo/Dobro passages, so that the smooth, blossoming notes from the Dobro were easily distinguishable from the staccato plucks and rolls of the banjo.
While testing the original and revised HE-400’s side-by-side, I noticed that when I switched the headphones while leaving the headphone amp’s volume control untouched, the rev 2 version of the HE-400 was much more energetic and really brought the music to life. I’d liken the sonic difference to the difference you might experience when switching between a 4-barrel carb vs. a 2-barrel carb on a well-tuned V-8 engine. Once you’ve installed a 4-barrel carb on your engine and really step on it the acceleration boost is incredible and it’s plain to see that the 2-barrel carb wasn’t giving you optimal performance.