If you’re into planar-magnetic headphones but thought power requirements and price limitations might put the damper on a purchase, think again. The smart hi-fi men at HiFiMAN have figured out how to deliver the sonic benefits of planar technology—noteworthy reproduction of finer details and spaciousness, for instance—in a high-sensitivity (98dB), low-impedance (22 ohms) can that isn’t power-hungry. In fact, the HE400S is so efficient it can be driven by your smartphone with no external amp required—a rarity among planar headphones.
These cans are also easy to use, and with non-fatiguing sound, easy to love (and at an entry-level price of $299, easy on the wallet, to boot). What’s more, the HE400S is capable of revealing the magic in music in subtle, yet affecting ways. (Examples to come.)
As I moved well past the recommended break-in period (150 hours) and into critical evaluation, the HE400S became my go-to ’phones for both travel and everyday listening, whether it was LPs, digital tracks of variable quality/resolution via Tidal or off my iPhone 6, etc. In fact, I’m listening to them as I write this review (some mellow Brian Eno tracks streamed via Tidal).
HiFiMAN is a relatively new company—founded by Dr. Fang Bian in New York in 2007 and headquartered in the port city of Tianjin, China—that specializes in personal audio players and headphones. Judging from its extensive product lineup from entry-level to reference, and its technological and design innovations, it’s clear HiFiMAN strives to continually develop new offerings for a competitive market—and nowadays headphones are among the hottest tickets around.
Let’s begin with the basics: The HE400S is an open-back headphone with fairly large round ear pads—which not only fit comfortably but allow greater surface area for the planar membranes housed inside them. (I’ll return to a brief description of planar technology and its benefits in a moment.) Weighing just 350 grams—slightly more than ¾ of a pound—they’re much lighter than they may appear to be in the photograph. Aesthetically, they have a slightly clunky look, but their appearance grew on me over time—the way I appreciated the boxy old Volvo I used to drive’s solidity by (and of) design. The “dual” all-black headband features an innovative suspension wherein a smooth, slightly padded, leather-look band rests on your head while a separate, slightly flexible metal band positioned above it provides the (gentle) necessary tension to position the cans. Adjustments are easy to make: Just slide the metal pieces that hold the soft band on either side up or down; small holes mark the options. Being a female with a smaller-to-average-sized noggin, I was pleased to discover that the ’phones fit me fine (set to about the snuggest fit possible). Soft, slightly plush black fabric covers the full-sized ear pads, which are removable. The light silvery, shiny chrome-look finish on the outer part of each can completes the picture. (I ended up with some scratches on the finish of the outer earpiece hinges.) I found the HE400S to be quite comfy, and their near-feather weight makes them ideal for long listening sessions or multi-hour flights.
Accessories are quite basic. There’s a ¼" headphone adapter and a (removable) 1.5-meter cable for the cans with a 3.5mm plug. (You can swap out the cable if desired.) A thoughtfully written, full-color, bilingual owner’s guide is included. A couple of minor quibbles: There’s no travel case, alas. Also, the included cable is covered in a soft, black, woven “fabric” that’s fairly tangle-resistant but prone to slight strain and wear around the connection points to the cans.
Regarding HE400S’ technical design, most TAS readers are familiar with planar-magnetics vis-à-vis dynamic drivers, but just in case, here’s the deal: Planar technology involves a diaphragm of very low mass that has conductive layers distributed throughout its larger (relative to dynamic designs) surface. This allows the diaphragm to be driven by magnetic force more evenly, resulting in lower distortion. From a sonic standpoint, this can translate into enhanced reproduction of subtle musical details in addition to improved soundstaging.
I’ll share some listening examples that describe how I experienced these characteristics and others. Note: Because I wanted to highlight the most approachable aspects of the HE400S, I’ve chosen to focus on the affordable analog and portable digital sources I tried—ones that seemed to suit these mid-fi ’phones—rather than get bogged down with expensive desktop amps. Across both digital and analog sources, in keeping with planar-magnetic sonics, a midrange focus emerged. The HE400S’ treble range is also quite respectable, as it benefits from the lighter mass of the planar diaphragm compared to dynamic drivers.