Thursday, 6 August 2015

HIFIMAN HE400S First Impressions Review: These Aren't the Planars You Are Looking For

After three seperate demos, I bought the HIFIMAN HE400S yesterday. I spent the evening listening and doing some listening comparisons with the AKG K712 and the Audio Technica ATH-R70x. I’m not a huge believer in burn in as a significant factor in changing the way something sounds (though I’m well aware of how powerful mental burn in is.) So here are my first impressions based on that amount of listening time.

Build Quality / Fit and Finish

The HE400S has poor build quality for a headphone for this price. The plastics chosen have a poor finish and my unit has a few glue marks from the factory. On the demo unit at Minidisc and my brand new unit, we noticed that at the rotating joint where the silver plastic meets the black headband clip, the black plastic leaves black marks as it rubs against the plastic. The grilles on the headphone are not fixed in place and can be moved around a little. On the plug of the right channel of the detachable cable, the sheath is roughly finished and I’ve noticed that it won’t seat itself entirely flush with the jack. 

I don’t think the headphone itself is going to fall apart or anything dire like that, but I would say the fit and finish of the headphone is below standard for this price. Compared to something like the Philips X2 or the AKG K712 / Audio Technica ATH-R70x and you can tell HIFIMAN still has a long way to go.


In terms of short term comfort, the HE400S is great. Big roomy velour earpads with a firm reassuring clamp, and a headband design that basically makes contact with my head across its entire length. 

At 350g, the HE400S is the lightest planar magnetic that HIFIMAN makes, but it is the heaviest headphone in my collection. The AKG K712 is 235g and the R70x is 210g. Compared to these featherweights, you can feel the extra 100+ grams of the HE400S in your neck. This is why despite loving the way some planars sound, I’ve never bought one. The HE400S’s light weight still does not close the ‘comfort gap’. 

Amplification / Source

I’ve been listening on my Objective2 as well as my Apogee Groove, though the HE400S can be driven by just about anything. The Groove in particular should be a near-perfect match for a planar magnetic like the HE400S. The Groove is a current source amplifier and should reduce the influence of certain mechanical / electrical problems on the sound of the HE400S, and the HE400S’s ruler flat impedance should mean it is largely immune to frequency response changes produced by the Groove’s necessarily very high output impedance. (This is a subject I’m preparing for my next review.) I have been told several times that electrical damping factor on planar magnetics should be a non issue because planar magnetics are mostly air damped. But lemme know if you know better.

This isn’t meant to be a review of the Apogee Groove, but I’m just saying that the HE400S should theoretically be sounding close to its maximum potential on a current source amplifier like the Groove. In practice it sounds to me just as good out of the ODAC or even my iPhone so far.


The HE400S is a very clean, neutral, balanced and pleasant sounding headphone. It’s smooth and somewhat relaxed, and it should probably should be grouped together with headphones like the AKG K712, Audio Technica R70x, and apparently going by Tyll’s comments, the HD600 (I haven’t had the chance to compare myself.)

There’s a bit of give and take between the HE400S and the AKG K712 and the R70x. The HE400S has some pretty gentle and smooth treble, and the sub-bass lacks emphasis and tends to sound a bit undercooked. The R70X seems to have more treble extension than the HE400S, making it sound more immediately detailed. It also has thicker and deeper bass, though not necessarily faster. I consider the R70X to have close to my ideal tonal balance - the HE400S just sounds a bit more gentle and relaxed on both ends but is otherwise surprisingly similar.

The AKG K712 has only slightly more bass than the HE400S, but it sounds tighter. The AKG K712 also has more of a forward mid section. Overall the AKG K712 sounds more vibrant and forward compared to the HE400S. I think the K712 is a better technical performer than the R70x and HE400S. It sounds more detailed and the bass is tightly controlled without sacrificing depth. But if you prefer a tiny bit more relaxed, less aggressive sound, both the R70x and HE400S aren’t too far off.

I should also note that the Philips Fidelio X2 has much more bass than any of the headphones mentioned here and while it might be tempting to compare the X2 to the HE400S based on price, I would say they offer very different sounds for different people. The X2 is great fun and I heartily recommend it, but it won’t win over neutral-heads.

The Take-Away

You might think I am commenting a lot on the bass, and I am, deliberately. The magic of most open planars is meant to be that they offer the benefits of an open headphone (lack of reverberation / echoes from the earcup leading to a more open sound, breathability and comfort) with the benefits of a closed headphone (stronger and tighter sub-bass response).

One of my favourite headphones which I fall in love with every time I demo is the HIFIMAN HE560. I love that headphone because it sounds detailed and open, but it has a near ruler flat bass response all the way down that just SLAMS. Whatever HIFIMAN did to reduce the cost and weight of the HE400S has gotten rid of that characteristic planar bass response. This can be confirmed both by Tyll’s measurements and just by listening to the headphone.

What you are left with is a planar magnetic headphone that performs roughly at the same level of other open dynamics at around the same price, except that it is heavier and has noticeably poorer build quality.

I want to be clear: I am not saying that the HE400S is a bad headphone or that it is completely anaemic in the bass or anything like that.

I am just warning people who may want to get HE400S just to see what the fuss is about with planar magnetics, that the HE400S doesn’t really share the same qualities. It takes its place as an alternative alongside the favoured open dynamics at this price range. It is not a giant killer. There is no ‘planar magic’ here.

So as a TLDR, if you are itching to buy one of these, here’s my summary of reasons why you would buy the HE400S and why you wouldn’t.

Buy the HE400S because:

- it’s slightly cheaper than other headphones (K712, HD600, R70x) at this tier.
- it doesn’t really need an amp and should be immune to the output impedance of most equipment, saving you money there as well.
- it has a smooth, relaxing, balanced, all round tuning.

Don’t buy the HE400S because:

- it’s a planar. That’s a bad reason because it doesn’t really sound that much like other planars. The one thing it shares with other planars is that it’s heavy.
- you think it might be some kind of super bargain. It’s not. It is priced appropriately to compete with other open dynamics on this tier. It is also more sloppily built than its competitors.

Personally, I would go for the R70x or AKG K712.