The tonal balance of the HE6 is most similar to Hifiman’s own HE5LE. The HE5LE noticeably sounds darker with more bass presence. This makes the HE6 a little less dark, though still quite far from the bright sounding HE5. Bass is more controlled and tighter on the HE6, where now the HE5LE sounds a bit boomy in comparison. Punch and impact is more precise on the HE6, though the slightly looser HE5LE bass may give an impression of a stronger bass punch. Midrange presence is also better in the HE6. It’s a good thing that Hifiman made this change, as now the HE6 has a more engaging upper mid than the HE5LE.
Treble quality is probably the first difference that people will notice though. The HE6 has a very clear and high resolution treble, clearly well above the levels of the HE5LE. The HE6 treble is even more impressive than the Omega2 with its slightly soft and laid back treble. The HE6, in comparison has a more linear sounding extension to the top frequency, though extension is still not as good as Sennheiser’s king of technicalities, the HD800. Detail level is better than the HE5LE, and should closely rival the Omega2, though still below the HD800. I didn’t feel too many change in the soundstage from the HE5LE to the HE6, and I would rank both of them more or less equal in soundstage performance. Ergonomics, sadly, remains pretty much unchanged from the HE5LE. The pads is still the most uncomfortable to wear, especially compared to the other $1,000 offerings. The HE6 is also noticeably heavier than the HE5LE.
Amplifier requirements on the HE6 is quite heavier than the HE5LE, though this production version is more sensitive than the prototypes. When I first received the HE6, I was listening to mostly classical recordings which have noticeably lower output level than mainstream ones. For such recordings, the Beta22 amplifier that I was using (gain 5) didn’t have enough gain even at maximum volume. Even with a mainstream recording, I had to go up to 3-4 O’clock on the Beta22 to get to a comfortable listening level. With the Grace m902’s amplifier, it can get loud enough around 88 on the volume mark, but still not loud enough for classical recording, even on maximum volume level. The Hifiman EF5 and the Matrix M-Stage remains a sensible and easy way to drive the Hifiman Orthos. With the EF5, for instance I was listening roughly on 12 O’clock on low gain. Where the M-Stage was around the same mark at maximum gain level.
The Beta22 clearly gives the clearest sounding signal and the highest resolution level. Soundstage was also the widest out of the Beta22. But somehow I felt that the music was not happening. Vocals didn’t have a strong focus and presence on the Beta, and the whole thing sounded un-involving. The Grace m902 was not that good of a match either. Sharp treble, and the same un-involving vocal like on the Beta22. The Hifiman EF5 with stock RCA Clear Top tube and OPA627 was the most ideal pairing. It didn’t have the resolution level of the Beta22, but the vocal has a very good presence on the EF5, a much better focus on the vocal, and better depth on the soundstage, though narrower than the Beta22. The M-Stage with the OPA627 also make for quite a good pair with the HE6, though still less than the EF5. The M-Stage has more bass body than the EF5, which is welcome, but treble is less clear than on the EF5 amplifier. Vocal presence on the M-Stage betters that on the Beta22 and the Grace m902, but still not as good as on the EF5.
It’s probably surprising that I rank the EF5 and the M-Stage as better amplifiers for the HE6, compared to top class amplifiers like the Beta22 or the Grace, but let me explain more.
The HE6, like its HE5 and HE5LE brothers, come with a weak focus in the vocal. On a good system, you should be able to feel the main vocal taking a presence right in front of you in the center of the stage. This is a very important factor of Hifi reproduction. Dynamic drivers may lack the precision and the transients of planar, but their conical shaped driver makes it relatively easy to maintain a center focus. Planars, which include electrostatics and orthodynamics, have a bigger challenge to accomplish this center focus. And I’ve witnesses this on all the planars design from the vintage orthodynamics and electrostatics, to the flagship Omega2 Stax. Somehow, due to the nature of the EF5 and the M-Stage circuit, both amps are able to deliver better focus on the vocals, while at the same time filling in the center-front soundstage portion. For most people who listens to music, vocal is very important, and this aspect will make a big difference on the music experience. Second, the HE6 and the HE5LE is quite transparent of the components up the chain, but somehow they are less critical of the amplifier resolution behind it. I can still notice the difference in the amps, but resolution in the amps becomes less of a factor than if I was using the HD800. Hence, I felt that the qualities offered by the EF5 and the M-Stage amplifiers, particularly in giving the orthodynamics a proper center focus, far outweighs its lack of refinement when compared to the Beta22 or the Grace.
The HD800 remains to have a more superior soundstage reproduction, not only in keeping a good focus on the vocals, but also the layering capabilities are far superior than the HE6, though it doesn’t have as black background as the HE6. What’s nice about the HE6 is that its sound signature are easier to like than the HD800’s. The clarity from top to bottom is also something that will impress a lot of people, while not adding any harshness into the mix. People will also appreciate the predictability factor of the HE6, as it continues to deliver a fairly consistent sound signature on different amplifiers, where the HD800 seems to varies anywhere from sublime to mediocrity depending on the set up.
I may still on the honeymoon period, but I’m fairly sure that the HE6 will do well in a battle against the Omega 2 or the LCD-2.