Conclusion: The AKG K391 NC is a powerful pair of noise canceling in-canal earphones with enough upsides to compensate for its merely average noise cancellation.
Pros: Powerful bass response and distortion-free, crisp sound signature. Outputs audio in both passive and powered modes. Charges via USB rather than inconvenient disposable batteries. Inline remote control and microphone for mobile devices.
Cons: Noise cancellation isn't class-leading. The inline compartment will be an annoyance for some. Bass-boosted sound signature not for purists.
Excerpt: 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.
Excerpt: The term “noise canceling headphones” almost always summons images of big puffy over-the-ear numbers. As wonderful as those can be, they’re bulky to pack if you’re traveling light, and during workouts, they suck — providing a feeling akin to sweating with scones strapped to your head. Austrian headphone maker AKG’s K391 NC headphones ($200) offer up noise canceling features in a compact package.