The HiFiMan HE-400i are great reference headphones specifically designed for critical listening. They have an excellent sound, on par with the Edition X but slightly sharper and with a bit less bass. They're comfortable and durable. However, they're not causal headphones so they won't be versatile enough to use outdoors.
- Great sound quality.
- Sturdy, durable build.
- Sensitive to ambient noise.
- Big and bulky.
- High leakage, cannot be used in public.
The HE-400i are well-built reference headphones. They have a lightweight, metallic frame that feels sturdy and durable. They're comfortable to wear for long periods of time and the ear cup hinges are also a bit better built than the Edition X. However, these are big, bulky critical listening headphones, and they're not intended to be used outdoors or while doing any kind of physical activity.
The large and open ear cups of the HE-400i have a metallic finish and a slight blue tint that's eye-catching. That coupled with the soft suede padding and the old school leather headband give them a retro, yet premium appeal that will work for some. They're a bit too bulky to wear out in public, but they're not designed for outdoors so it shouldn't be too much of an issue.
The HE-400i are comfortable, well-padded headphones. They're not too tight on the head, and the suede-like material used for the padding is soft and pleasant on the skin. The ear cups are not as large as the Edition X, and the padding touches the tips of some listeners'ears. However, this smaller format might be more comfortable for some, than the oversized ear cups of the more premium model.
These are not sports headphones. The large over-ear cups, will sway and quickly slip off your ears if used during exercise or while running. They're a bit more stable than the Edition X and will maintain their position during casual or critical listening sessions.
The HE-400i are big and not portable. They're bit too cumbersome to comfortably carry on your person and do not fold into a more compact format. The ear cups lay flat but are bigger than average over-ear models, which doesn't save much space. On the upside, they are a little smaller than the Edition X but you will still need a backpack or a large bag to transport these headphones. Also they don't come with a protective case or pouch.
The HE-400i have a good build quality. They make use of premium materials, which results in a sturdy design that can handle a fair amount of physical stress. The ear cups are not as well-built as the Edition X's ear cups. However, the plastic joints connecting the frame to the ear cups is thicker and sturdier, which makes these headphones slightly more durable.
The HE-400i have a great sound quality, with wide and open soundstage and a balanced audio reproduction. Instruments and vocals are evenly represented, bass is punchy and not overpowering although it lacks a little low-end rumble compared to the Edition X. The higher frequencies, on the other hand, are a tad inconsistent. There are peaks in the treble range that cause some lead instruments to sound a bit too sharp and piercing.
Good Bass Range performance. Low-bass is extended down to 49Hz, which is decent, considering the open architecture of these headphones. However, this means low-bass could be slightly lacking in rumble and thump. High-bass is hyped by about 2dB, adding excess warmth and muddiness to the sound.
Excellent Mid Range performance. The response is flat within 2dB of the target response, but the tilt favoring low-mid could slightly push the vocals to back of the mix.
Average Treble Range performance. Low-treble is well-reproduced, although the 6dB dip surrounding 5KHz could negatively affect the clarity and detail of leads/vocals. The 6dB bump in treble makes these headphones noticeably sibilant, which could sound too sharp to some. The 12dB peak at 9KHz, although quite noticeable, won't sound as loud as it looks, due to its narrow width.
- 100% Avg. Std. Deviation
Very good soundstage. The deep and angled drivers of these headphones perform similarly to the HD 800 S in the PRTF test, pulling out the soundstage from inside the head to the front. Also, these headphones are extremely open, and one of the loudest we have measured so far. This will help the music merge with the outside ambience, and at higher volumes even activate the ambient acoustics.
Average Imaging. There is noticeable phase shift present in the Treble, but lower frequencies show minimal phase error. The drivers of our test unit were quite well-matched in terms of amplitude and phase, and even frequency response which seems to be a downside of Planar Magnetic headphones as it is more difficult to keep a low manufacturing tolerance.
Excellent harmonic distortion performance. The response looks quite jagged, which seems to be typical of Planar Magnetic headphones. However, the more narrow-band spikes won't be audible to most. The amount of harmonic distortion at 90dB SPL is quite good, though, there is a noticeable rise in the amount of harmonic distortion at higher volumes.
The open-back design of HE-400i is purposely meant to leak and poorly isolate listeners. This improves the sound quality by creating a wide and immersive soundstage but this also means, the headphones cannot be used outside effectively. They will most likely distract anyone around you with their leakage level and they will be practically unusable in loud environments.
Poor isolation. The architecture of these headphones is completely open, and block very little. They provide no isolation in Bass and Mid ranges, and provide only 7dB of isolation in the Treble, which is negligible.
Poor leakage. These are the one of the loudest and leakiest headphones we have measured so far. Not only the level of the leakage is extremely high, the profile is extremely broad too. Most headphones either level off at higher frequencies, or roll-off, but similar to the Edition X, the HE-400i keeps getting louder as the frequency rises.
No active features.
No compatible app.
In the box
- HiFiMan HE-400i Headphones
- 1/8" to 1/4" adapter
- Audio cable