AKG K391 NC In-Ear Headphones Review


Up until this point, noise-canceling headphones were all a bunch of poorly designed pieces of cheap plastics costing a lot more that you've bargained for. Recent outings namely from Harman Kardon, changed all that with an attentive touch for good design. AKG is known to make great sounding gear, and if you don't plan on purchasing the company's $1,300 set of technologically advanced K3003 in-ear headphones, then how about their second most expensive set at $200. It comes as no surprise that AKG, now a Harman owned Austrian audio brand, released arguably one of the best looking active noise-canceling in-ear headphones in their class. The K391 NC are in-ear headphones with active noise-cancellation out to recreate studio quality sound with the serenity of unwanted ambient noise inside your ears. Join us after the break as we take a deeper look at AKG's K391 NC!


Noise-canceling bearing in-ears headphones never appealed to me, ever. We've even reviewed a pair made by Phiaton, and quite honestly I think they are hideous and poorly constructed. Design is not a concern for the K391 NC let me tell you that. It can be said that these are the best looking active noise-canceling in-ear headphones currently available, and we've made sure to do our research prior.

While not as poised as AKG's K3003, the K391 NC have distinctive bold, silver metal enclosures finished with a brushed metal look and sport a well rounded shape that is somewhat mundane yet also sufficiently appealing. But then again AKG isn't particularly known because of its mainstream design, but instead the brand is more focused on sound than creating the next Beats by Dre competitor. The theme of machined silver metal and black rubber plastic really stands out as contemporary, and would probably fit well with a handful of other devices and accessories you may already have. Another detail that may not be clearly spoted thru the photos is the use of a machined swirl accenting the ends of each metal enclosure.


A quick overview of what you get inside the packaging reveals the in-ears themselves of course, as well as a few extras like an airline adapter, different silicon tip sizes, a micro-USB to USB charging cable and two high quality, detachable short 3.5mm audio cables sporting a case-friendly slim metal connector plug. You'll only use one of the two silver or black colored connector equipped cables, but AKG was courteous enough to let users pick which color they would like to use. Also included is a black storage pouch. AKG mentions that a "premium hard case" for the iPhone is also included. Disappointingly, there was no sign of it anywhere so don't expect to find it.

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Style is of course a subjective manner, but build quality? Not so much. Naturally, the K391 NC's all-metal enclosure construction makes them seem ultra tough, and they are. The black stems aren't made from metal, but from plastic so I would be more cautious when replacing those silicone tips. With that being said, I don't foresee any issues with durability down the road even if you tend to abuse your in-ears. Because of their substantial size and solid construction, the K391 NC aren't as fragile as some other in-ear headphones we've tested. The cables we think aren't tangle-free, and AKG hasn't mentioned them to be. But they're thick and durable, and not once have I experience them tangle.

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The K391 NC have a very particular set of features; features that make them impervious to noisy situations. And I'm of course talking about the active noise-canceling feature, which is obviously the biggest feature of them all.

Active noise-canceling designed brilliantly!

One thing to consider is that in-ear headphones that boast active noise-canceling features are more often than not bulky in size, and currently all require some form of an external power source to power them on unlike built-in power sources found in full fledged headphones like the Harman Kardon NC and Logitech's UE 9000. This is where the in-line power module comes into the picture. First thing we can notice is that it's really well designed and matches the overall brushed metal theme of the K391 NC.


Switching on the unit turns on a green light indicating that the active noise-canceling feature is working. The module is essentially a rechargeable battery that provides the power and the know-how technology that powers the K391 NC's active noise-canceling feature. As soon as you turn it on, you'll notice a change in the clarity of audio. Depending on the type of background noise, you'll also notice that the K391 NC cut down on the amount of ambient noise around you. Sitting right next to an air purifier blowing out air on high making similar cabin noise you'd experience in a flight, turning on the ANC helped reduce the noise in a surprisingly noticeable margin. The same isn't so apparent with people talking next to you.

Prolong battery life even the Energizer bunny can't match

One of my worries were that I would have to spend a considerable amount of time recharging the battery on the K391 NC, and quite often too, which fortunately isn't the case. The battery life is off the walls amazing. AKG claims roughly 35-40 hours of playtime, 40! Usually such claims fall short, but not in this case. Battery life is outstanding. I've left the unit switched on before going to bed, and the next morning I was astounded to be greeted with the green power light still shining strong; and plenty of battery left to last me for the following next two days. To recharge the device back up, all you have to do is plug it into a USB adapter using the supplied USB charging cable. The built-in rechargeable battery is such a convenience, a feature that's hard to come by when it comes to such active noise-canceling headphones.


Before I started using the K391 NC for the first time I convinced myself that it'll just be a burden on my user experience because of its active noise-canceling feature which meant that I would have this small powered battery module dangling on my cable and essentially becoming a total nuisance. Now that I have spent a considerable amount of time using these in-ears, I admit that I was wrong to think that.

AKG being the Austrian audio engineering company that it is, was smart enough to design the K391 NC in a way so that the power module is situated so low down the audio cable that it'll never be able to pull down on the cable. It's placed where you can actually just slip it into your pocket all while you still have enough slack on the rest of the cable running up your body. Not to mention the active noise-canceling module is already very slim and extremely compact that it doesn't get in the way of things.


The reason why the K391 NC's driver enclosures are larger than the usual set of in-ears has to do with the placement of the microphones placed in each speaker housing which listen to ambient noise in order to cancel it out when the active noise-canceling unit it switched on. With that said, the difference in noise cancellation isn't breathtakingly significant.


If you're still following along, the K391 NC feature a Apple-product compatible in-line headset remote with mic. And again, AKG is misleading when it claims that it's a 3-button remote when in fact it isn't. Instead, you'll have one button to answer and end an incoming call. Having no volume or music controls is always a deal breaker and a disappointment when paying $200 nonetheless. The least we expected is to find a similar remote and mic module that Harman Kardon ships with all of its headphone offerings.

There's still some good to point out however. The mic has no trouble picking up voice, in fact it's very sensitive so you can talk quietly and you'll be heard loud and clear. And overall, the audio quality is remarkably good. It's crystal clear, loud, and very clean. All in all I'm very pleased with the performance of the mic, it's a powerful headset module that'll be a useful tool when Skyping and even general voice recording. It does however, pick up background noise easily.

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Although the K391 NC are significant in size, they're actually lightweight and fit comfortably inside the ear canal. The stems which fit into your ear are angled slightly, and instead of inserting straight, they follow the natural path of your ear canals so that you get a tight fit just like the Denon AH-C 560R. I've worn these for hours and haven't felt any discomfort or the feeling of movement. With the right silicone tip size, the K391 NC will never fall out of your ears and will remain snug.  


Sound quality wise, the K391 NC perform much like a $150 pair of in-ears - notably similar to the NS600 Crush by Nocs. The two also share a very similar build quality made using the same materials. The only difference is the active noise-canceling feature that comes with the K391 NC. Overall, the sound signature is on the balanced side; highs bring a lot of clarity up front with a clean detailed sounding midrange that isn't overshadowed by the high and low end. It's also worth noting that the K391 NC aren't as bright sounding as the NS600 Crush, but come very close and instead sound slightly warmer as a result.

Bass isn't being projected at excessive amounts, but at a controlled and well restrained manner. It isn't going to appeal to you if you like yours served with a not so healthy portion of thump, however, if you care less about the drop and more about the rest of the notes - the K391 NC have an accurate and balanced sound signature with enough warmth and details that delivers a clean quality sound good enough to be used for referencing. I could use more bass to satisfy my thirsty requirements for "thudness". I should note that there is plenty of quality bass here to appreciate. The K391 NC have a natural and accurate sound signature, which means the bass kicks in when called for and isn't present and overly saturated in every single piece of music.


Of course there's perhaps the most noticeable difference of when turning on the active noise-canceling feature, which is that the audio becomes a lot more alive. Sound is richer and amped in volume by the battery powered ANC module, and if you haven't noticed, that has become a standard occurrence that we've come to expect with anything that claims to feature active noise-cancellation that requires its own a power source which really helps in amping the audio so that it ends up sounding better compared to only having your audio source drive power to the headphones.


AKG's K391 NC are indubitably the in-ears to get if you want active noise-cancellation

I was hoping the K391 NC would become my party buddies, but they're too calm and reserved for my taste. Although that definitely doesn't mean people who want to listen to audio with in-ear headphones that are capable of reproducing sound that's natural, balanced with clarity and detail won't fall in love with the K391 NC; because the do sound excellent. They're an absolute pleasure to use considering an external power source is involved, they've got outstanding battery life and a svelte industrial design. Did I mention they also sound terrific? We expected a good time, and AKG delivered.

As for the noise-canceling performance, the K391 NC do block out external ambient noise, but not in a considerable amount that you'll clearly be able to tell a difference between a normal set of in-ears fitted with foam tips. What is more noticeable when using the active noise-canceling feature on the K391 NC is that instead of making it sound as if your music is isolated along with the background noise, you never lose the brightness and clarity in the audio signature which is outstanding. Although we do recommend the K391 NC and think they're the best looking and even performing set of active noise-cancelling in-ear headphones currently available, they lack a functional 3-button remote control. Fortunately, that's about the only drawback we could find.

Passive noise isolation using foam tips is still our preferred remedy for cutting out unwanted ambient noise and excessively loud people. The selection is broader and less expensive, respectively.