COST: $399 (CAD – Amazon.ca) $299 USD
TYPE: Open, Planar Magnetic, Over-Ear
DRIVER SIZE: Diameter 80 mm
FREQUENCY RESPONSE: 20 Hz – 35 kHz
EFFICIENCY: 98 dB
NOMINAL IMPEDANCE: 22 Ohms
WEIGHT: 350 Grams
Headphone Adapter – 3.5 mm to 6.35 mm
Headphone Cable – 1.5 meter, 3.5mm 90-degree angle plug
Cardboard box with foam padding on the inside
Build Quality, Aesthetics and Comfort
While there have been reports of earlier model HiFiMan headphones having less than desired build quality, thankfully this is not the case with the 400S. Overall the quality, fit and finish of the materials is very decent. The headband pad is pleather and other than the headband arch and side grills, all visible materials are plastic. The 400S has the new HiFiMan style headband and angled ear pads, which are covered in a very comfortable black velour material.
Especially welcome is the use of removable 2.5mm female mini-jacks on the ear cup connectors (like the HiFiMan HE-1000, or Sennheiser HD 700), rather than the older screw-on type. Use of plastic for much of the construction and the newly redesigned drivers (half the magnets of other models), means that the 400S weighs about 20-25 grams less than other HiFiMan headphones. The planar dynamic drivers can be seen in direct light through the exterior grills of the ear cups.
Overall this is a very comfortable headphone. The circular ear pads are large enough to accommodate most ears. The relatively low weight and headband pad design combine to rest easily upon the head, and the clamping force of the headband is not too strong for extended use. The headband, pad and cups offer a good range of movement to accommodate a variety of head sizes.
I only have 2 complaints. The included cable is wrapped in a paracord material and is quite stiff, making it unforgiving and at times frustrating to use. Due to its detachable design, this can fairly easily be replaced. I’m also not in love with how the 400S looks when wearing. The squared off metal band with the pleather hammock headband is, as noted above, absolutely functional and comfortable. However, coupled with the large circular ear cups, it is a bizarre contraption for your head. To best describe the headband look, is to picture one of those large black paperclips with the fold-back silver arms, clamped solidly on a GI Joe action figure’s head (right over both ears). This is the very silhouette that the headband on the 400S achieves.
Sound Signature and Quality
The 400S is a superb sounding headphone. It has been described as being entry level, of not delivering the same visceral experience as other (more expensive) planar headphones, of sounding more like a traditional headphone than a planar, and of (most likely) not meeting other expectations of other reviewers. However, for sound quality (and especially at this price point) it is an extraordinary sounding headphone. I will compare it to the previously similarly priced Sennheiser HD598, an excellent bang-for-the-buck dynamic headphone, as I am intimately acquainted with this model.
Clarity and coherency is very good. It is smooth and musical with a slightly warmer than neutral sound signature. The midrange shines with excellent imaging, and noteworthy realism and transparency. The 400S is extremely easy to listen to and non-fatiguing, with a natural sense of space and vocal presentation. Compared to the Sennheiser HD598 the 400S has a better presence and sense of engagement.
Midrange in the 400S is very enjoyable and smooth. It has good body and detail, and maintains clarity and musicality. Voices are engaging and intelligible, as they should be.
Treble is on the softer side but clarity and detail are maintained. While not sounding greatly extended, it’s never harsh, nor dark. Compared to the Sennheiser HD598, the treble extension of the 400S does not sound as bright.
Bass has too much body to be classified as neutral (note: which I find appealing) and sounds more like the bass expected from good dynamic headphones. It is worth mentioning that changing the ear pads to Hifiman Focus noticeably improves bass response. With the included pads, the 400S lacks low bass extension (or slam) but does remain fast, tight and without distortion. It also achieves greater low bass extension than the HD598.
I believe strongly in the concepts of bang-for-the-buck and the law of diminishing returns with music playback equipment. Although the HiFiMan 400S is one of the least expensive planar headphones ever available, they provide much of the clarity that is inherent in planar type headphones (while admittedly sacrificing some of the bass slam) and they uniquely bring the ability to be driven well from a portable player or inexpensive amplifier, while also combining light weight and remarkable comfort. While this entry-level for audiophiles price point stretches my own tight budget, the 400S certainly delivers with excellent sound, comparable to much more expensive models and to some of the most respected dynamic headphones available.