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HiFiMAN HE400S Review – Best Sub $300 Open-Back Headphone?

HiFiMAN HE400S Sound Quality and Subjective Listening

HiFiMAN HE400s Planar Headphone Review-22

Before I begin, I just want to mention the gear I used for this review:

  • DAP: Luxury & Precision L5 Pro, the Bit Opus #1
  • Smartphone: iPhone 5
  • DAC / AMP: iFi iDAC2, iFi iCAN SE, ALO Audio CDM
  • Music Files: Most are lossless FLAC files

The HiFiMAN HE400S is a planar headphone so I don’t think it needs a long burn-in period unlike most dynamic driver headphones. However, it was necessary for me to do some mental burn-in since I was very used to the Grado SR225e‘s sound signature. The first few days of using the HE400S, my ears missed the detailed and well-extended treble on the SR225e and the somewhat right on your face mids. Ironically, when I first used the SR225e, those were ear piercing for me. It was only until a number of hours of burn-in period that the treble became tamed and my ears were able to adapt to the SR225e’s sound signature. So to be fare with every headphone I test and audition, I have to do some mental burn-in and ear conditioning as well.

After a month of testing and listening with the HE400S, I find it to be a neutral sounding headphone that is leaning towards the warmer side. It was generally musical and definitely fun to listen with. But the big difference I noticed with the HE400S compared to my SR225e, and specially to my closed back headphones, is its sound stage. It just blew me away. The sound stage is definitely above average. I can’t say phenomenal at this point since I know the higher end ones, specially the HE1000, have better soundstage and imaging.  But it’s definitely better than any closed back headphone I have listened to before.

When I listened to Amber Rubarth’s Sessions from the 17th Ward album, her voice sounds like she is just singing in front of me and the instruments are just right beside me. It feels that the music is around me and not in my head. It doesn’t seem that the HE400S has a very wide soundstage but it was definitely wide enough to fool me that someone was knocking on my door when I did some binaural tests. Like I said, the sound doesn’t feel that it’s in your head, it’s very spacious and the feeling is relaxed and there’s no pressure building up.

The sound that the HiFiMAN HE400S produce is very clean and well balanced. However I’m not sure what HiFiMAN did to its driver (probably reduced magnets), since it sounded more akin to a dynamic headphone (only better), instead of a full pledge planar headphone. Audeze’s EL-8 is a planar and the way it produces the sound was a bit different compared to the HE400S. I’m not comparing them in terms of sound quality and signature, but like I said the HE400S sounded like it’s a dynamic headphone rather than a planar.

Most people nowadays, specially the young ones are fond of bass heavy headphones. Well the HE400s has a good amount of bass. It’s controlled and somewhat tight, but it’s definitely not dominant nor does it overpower the mid-section. Even though the bass in this headphone is good, it doesn’t have that kind of impact or slam that you get from a warm closed back headphone like the Master & Dynamic MH40 or the V-MODA Crossfade M100. To my ears, while it doesn’t give you that thunderous and very deep rumbling sound that bassheads loved, the HE400s offers a clean and well-articulated bass, enough to enjoy the music. The good news is that some users report that by using a FocusPad, bass response is a bit improved, but with a trade-off from the treble frequency. I haven’t tried it yet personally, but I’m looking forward in experimenting with other type of pads when I get a pair or two.

On the opposite side, the HE400S offers a smooth and relaxing treble. To my ears, it’s extended enough to give it a bit of sparkle, clarity and detail to the music without being sibilant or ear piercing. I’m not quite sure why others claim that the HE400S is sibilant, but its treble frequency is definitely unlike with my Grado SR255e. I think it’s nowhere near of being edgy or analytical at all.

A headphone with a bad mid frequency is really a bad headphone and you should definitely stay away from it. However, a headphone with good or better mids is definitely worth auditioning and the HiFiMAN HE400S is sure enough to be in this category. The mids is where the heart and soul lies and the HE400S has a great midrange tuning. To my ears it’s a bit forward leaning, but not in your face forward and definitely not veiled at all. The mids is so clear and clean that it gives you that connection to the artist’s voice. I was so amazed with how articulate the mids are, and it certainly has great vocal clarity and amount of detail. The mids in this headphone is easily my favorite and it’s even better that some of my more expensive headphones.

One thing I also like about the HE400S is its ability to be driven easily, even with a smartphone. Like I said earlier, even my iPhone 5 can drive it and still provide plenty of volume. It doesn’t really require a dedicated amp, as long as your source is capable enough you should be fine. You don’t need a really good amplifier to make this headphone sing. But pairing it with a good AMP/DAC certainty has benefits. For example, for a number of weeks, my primary source was the iFi iDAC2 (since I am reviewing it as well). A few days before I wrote this review, I decided to use the ALO Audio CDM as my source. I was listening to Meat Loaf’s I’d Do Anything for Love and suddenly I realized that everything sounded better. It was as if I was using another headphone and not the HE400S, wow! Just wow!

I don’t want to give you the impression that you need to spend on a DAC/AMP like the CDM to make this headphone sing. HiFiMAN’s goal with the HE400S was to bring hi-res and hi-fi audio in a planar setup to a more affordable price range. Just like what Andrew Jones is doing with his current Debut speakers. I’m just pointing out that if you ever get a change to acquire a better DAC/AMP, that would be a bonus.

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Author
Peter Paul
Peter is a PC enthusiast and avid gamer with several years of hands-on experience in testing and reviewing PC components, audio equipment, and various tech devices. He offers a genuine, no-nonsense perspective, helping consumers make informed choices in the ever-changing world of technology.

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