Review: AKG K391 NC Active Noise-Canceling In-Ear Headphones with Microphone
Company: AKG Acoustics
Compatible: All iPads, iPhones + iPods except iPod shuffle 3G
A half-decade of active, high-profile in-ear earphone innovation began to stall out two years ago with the ascendance of Monster's Beats by Dre headphones, which were heavily marketed to consumers as large, highly visible fashion statements rather than on compact size or sonic quality. The success of Beats led many rivals to focus on creating similar-looking glossy headphone housings or paying for celebrity endorsers, but thankfully, a handful of companies kept toiling on technical and sonic improvements as well. Today, we're looking at three recent earbud and canalphone designs -- AKG's K391 NC ($200), Audio-Technica's ATH-ANC33iS ($80), and Logitech UE's Ultimate Ears 900 ($400, aka UE 900) -- as well as a high-end pair of over-ear AKG headphones called K551 ($380). The smaller headsets are some of the best we've ever tested, while the largest one is a surprisingly big disappointment.
Austrian headphone maker AKG is owned by Harman International, best known in the Apple accessory world for its numerous well-designed Harman and JBL-branded speakers, as well as lines of premium and budget headphones. Relative to what’s come before, K391 NC is a decidedly mid-range model—considerably smaller and more affordable than the Harman Kardon-branded “NC” headphones, while both sexier and pricier than budget alternatives such as Audio-Technica’s ATH-ANC33iS. K391 NC consists of a pair of small, silver brushed metal canalphones with a one-button remote and microphone dangling from the left earphone, plus a matching noise-canceling module centered on the lower part of the black cabling. Two highly case-compatible 3.5mm audio cables are included, one with silver housings and the other with black housings, each running 19” from the connection port at the bottom of the noise-canceler. AKG also includes an airline adapter, fabric carrying pouch, and three sets of silicone rubber eartips in each package; however, our review unit had no sign of the “premium hard case for iPhone” mentioned on AKG’s web site.
One critical differentiator between K391 NC and the less expensive Audio-Technica model is the noise-canceling box. Sleekly designed to match the canalphones and cabling, the slender silver metal and black plastic box has a 35-40-hour battery inside and a Mini-USB port on the bottom for recharging with an included USB cable. It’s extremely uncommon to find a rechargeable battery in a pair of noise-canceling earphones like this, so even though the lifetime cost of buying AAA batteries mightn’t itself make up for the price difference between models, the convenience factor of USB charging is certainly worth something. A switch on the top turns the noise-canceler on and off, leaving the earphones working even in the unlikely event of a power outage, albeit with diminished dynamic range. This is a common if not universal limitation of active noise-canceling headphones, and acceptable given that Bose noise-cancelers historically didn’t work at all when their batteries ran out.
Unlike Audio-Technica, AKG provides no specifications or even estimates as to the active noise-canceling capabilities of the K391 NC; it’s common for companies to suggest ambient noise filtering in the 80-90% ranges, even if those numbers are somewhat iffy. Compared with the supposed 90% capabilities of the ATH-ANC33iS, which is capable of muting the voice of a person speaking right in front of you when the earphones are turned on and playing music, K391 NC’s system isn’t quite as strong, letting a bit more mid-frequency noise in at low to medium music volumes. The difference isn’t night and day, but it’s there. Still, you’re unlikely to notice or be bothered by what modest amounts of ambient noise remain, as your music will be dominant; those merely seeking reduction of the low-pitched engine noises common in airplanes and trains will find it here.
The other key differences are in the canalphones themselves—the fit and the sound signatures. Some users might see K391 NC as another variation on the hybrid earbud/canalphone design, using relatively large housings to hold audio drivers and ambient noise-sensing microphones that rest just outside your ear canals, while angling small rubber-tipped pipes into your canals as channels for the sound. However, the tapered tube-like K391 NC shapes are less like earbuds than the ATH-ANC33iS, and their cool metal bodies feel nicer, with less tendency to accidentally fall out. AKG’s use of swirled silver metal with black accents also achieves a cooler look than the Audio-Technica design, as well as Harman’s 2012-vintage, awkwardly boxy AE + NI earphones. These are far from the smallest single-driver earphones we’ve seen, but the housings are nice enough that their size doesn’t work against them.
Sonically, the K391 NC holds its own as a premium-priced earphone. With the noise-canceler turned on, K391 NC delivers sound that’s particularly clean in the treble, midrange, and mid-bass departments, with enough bass to sound entirely competent rather than overwhelming. Overall, we’d characterize the sound as very nicely balanced and even more dynamic—higher highs and lower lows—than the ATH-ANC33iS, though the improvement in the highs is more pronounced, with particularly crisp treble that lets high-pitched beats stand out. If you turn the noise-canceler off, the audio flattens and drops considerably in volume, losing much of its midrange and bass prominence; the battery life and ease of USB charging reduce the likelihood that this will be necessary.
One somewhat curious omission in K391 NC is the absence of Harman’s nicely-designed three-button remote control unit—a sign, perhaps, of the continued design and engineering divisions between AKG and Harman’s other brands. This version’s microphone sounds nearly identical—and very good, our callers said, virtually indistinguishable from Apple’s—but there’s only a single button on the half-black, half-silver remote. As would be expected, this button can play and pause tracks, change tracks with multiple presses, start and end phone calls, and activate Siri; no buttons or dials are included for volume adjustment, so you’ll need to make those changes on the device itself.
Taken as a whole, K391 NC is a very good noise-canceling earphone option—a premium-priced model with just enough legitimately premium functionality to be worthy of considering. Between the nice industrial design, clean sound, and very welcome rechargeable battery, it represents a clear step up from low-end noise-canceling earphones, though its single-button remote and good-not-great active noise-canceling functionality both could be better. Like many of Harman and AKG’s recent headphone offerings, it doesn’t feel as aggressively priced as it could be given the specs, leaving a premium for industrial design and raw build quality. If its looks resonate with you, we’d certainly suggest that you take K391 NC for a whirl; you’ll almost certainly be pleased with the sound, and quite likely the rest of the package, as well.