One thing that is very true about headphones is that everybody hears them differently! Headphones are very subjective to your personal taste in sound and driver setup, which makes a huge difference to the reproduction of music.
While dynamic drivers and balanced armature drivers are the most popular driver setup found on most headphones and hybrid in-ear monitors (IEMs), not many dynamic headphones can compete with the vast scale of sound planar and electret headphones are capable of.
Electret headphones are a variation of planar, although their drivers are nowhere as large as the drivers inside a pair of planar headphones like the Hifiman HE400S (pictured). Check out also the new HE400SE magnet version!
The Hifiman HE400S are the perfect step-up for those looking to make a serious headphone purchase without going broke in the process.
Unlike many planar headphones, which are very expensive and heavy in weight, the Hifiman HE400S are relatively affordable and comparatively lighter (350 grams) than a lot of over-ear style dynamic headphones.
The Hifiman HE400S sit on the head relatively well, thanks to the suspension style headband, which has a dual configuration with the padding separated from the frame, which is made of solid aluminium with a black anodized finish.
The padding support is made of pleather with perforated tiny holes for ventilation. The padding is wider at the top (7cm) and narrower towards the bottom (5cm) so, it provides a large supportive area on the head. The padding, while very thin, doesn't cause heat spot since the frame of the headband is separated.
The headband padding is adjustable via plastic retainers on either side that you slide up and down. The headband makes a sliding notch sound and stays adjusted in place just like the HE400S model.
The yoke and outer shell of the earcups are made of hard plastic, while the perforated mesh on the front side of the earcups is made of metal.
The foam padding on the earpads is covered with plush velour fabric, which has a similar soft feel to real velvet, which is usually made with cotton or silk. Velour can also be made with cotton or polyester. It appears the velour fabric on the HE400S earpads are made of cotton because they don't make the ears sweaty like polyester would.
The foam padding on the earcups has been designed to be thicker at the top (2.5cm) and narrower towards the bottom (1.5cm), which allows for a more natural angle when the earcups rest on the head.
The diameter of the outside of the earpad is 10cm, while the inside diameter is 5.5cm, which will suit small, non-protruding ears since the depth of the earcup is 2cm and there is only a very thin layer of fabric separating the speaker driver. The earpads can be removed for cleaning. Replacement are available to buy online.
The HE400S earcups can be rotated 90 degrees either way (left and right), while the yoke allows the earcups to be tilted 180 degrees so, you can have the front side of the earcup rest flush on one ear, like a DJ, when mixing tracks.
Sound wise, the HE400S share similarities to the DEVA headphones, in terms of bass response, although the HE400S have better imaging, thanks to a massive treble range (up to 35kHz), which is clean and does not distort even at max volume.
To improve the fidelity potential though, you can hook up the HE400S to an external DAC amp, although one it's not required since the HE400S are low ohm headphones (22 Ohm) so, they can be easily driven from the headphone jack of a smartphone.
Volume-wise though, the HE400S volume output doesn't appear louder than the DEVA headphones, despite the fact the HE400S are more sensitive (98dB). This is, probably, likely due to the lower impedance rating (18 Ohms) of the DEVA headphones.
The included 1.5 meters long audio cable integrates three gold-plated connectors, namely a 3.5mm angled-plug connector and two 2.5mm mini straight-plug connectors that have to be inserted in each earcup. The audio cable is good quality, thanks to its nylon braiding sleeve which is more durable than regular audio cables made with a rubber sleeve.
While the 3.5mm connectors are gold-plated, the plugs (holding the connectors) are made of hard plastic, which is obviously not as rugged as metal audio plugs.
Aside from the audio cable and quarter-inch adapter, there is no hard-shell carry case included, although considering the open-back nature of the HE400S headphones, you aren't very likely to wear the HE400S outdoors.
That said, the card box the HE400S come packaged into it's very sturdy and has a foam insert cutout that doubles as a storage box. You can buy the Hifiman HE400S planar headphones from Amazon.