The AKG K490-NC are decent-sounding, noise canceling headphones. They lack a bit of bass but they're decently comfortable and have a somewhat sturdy build quality. They barely leak, they're somewhat portable and they're stable enough to run with but won't be the best headphones for sports. They also have no practical controls apart from the NC switch which is slightly disappointing.
The AKG K490-NC have a simple and clear design but suffer from build quality and functionality issues. The thin headband and many potential weak points make the K490s prone to breaking. They have no in-line control options either, which is disappointing. However, they are relatively comfortable for an "on ear" design.
The AKG K490-NC look great. The silver accents from the polished metal give them a premium look. The thin headband is lightly padded. The small on-ear cups are circular, well-padded and have textured plastic backs with the silver AKG logo branded upon them. The branding works well with the overall look and is not overstated.
The button layout is quite simple. There is only a button for noise cancellation and nothing else. No in-line controls or mic on the cable, which is disappointing.
The K490-NC are decently stable headphones. They apply enough pressure to your ears to stay in place during casual listening sessions, and their lightweight, compact design prevents them from swaying too much during moderate physical activity. They also have a detachable audio cable that won't pull the headphones of your ears if it gets hooked on something. However, they're not sports headphones and will slip off you ears while running.
The AKG K490-NC are mid-sized on-ear headphones. They're moderately portable and don't take up too much space in a bag. They also fold into a more compact design for easier storage and transport. They will fit comfortably in a jacket pocket but will be too big for regular pant pockets.
These headphones are quite well-built for the most part, but have a few major weak points, mainly the joints, that may spoil the whole experience. Also, the headband adjustment slider is very loose and easily loses its position. There are some customer reports on Amazon.com regarding the hinges breaking.
The AKG K490-NC is an average sounding pair of closed-back on-ear headphones. They have a mediocre sounding Bass which lacks sub-bass, a Mid Range that sounds a bit boxy, and an average sounding Treble which lacks a bit of presence. On the plus side, they produce very little distortion.
The AKG K490-NC are not going to isolate you very well. The noise canceling is sub-par at best but will at least keep sharp ambient noise at bay. They shouldn't be your first choice for noisy commutes or traveling. The seal provided by the ear cups, on the other hand, is decent for an "on ear" design and leak very little sound.
Surprisingly, the AKG K490-NC has a rechargeable battery that lasts as long as some of the headphones that use disposable AAA cells. Granted they only have noise canceling as an active feature, which makes them less versatile for other use cases than noise canceling headphones, lacking both wireless or an app, to enhance and customize sound. However, at 46 hours of battery life, they will easily last a weekend without needing a recharge.
The AKG 490-NC have a long lasting battery life. They provide up to 2 days worth of continuous play at average volumes. They take a bit longer than average to charge, but it shouldn't be much of an issue has you won't need to recharge through out the day thanks to great battery life. Unfortunately the audio cable and charging cable share the same port and cannot be used at the same time. Hence, you won't be able to play audio while charging.