These headphones are ideal for long flights. In addition to having overall impressive noise-cancelling (-33dB across all frequencies on some tests), these headphones excel when you need to cancel out low frequencies like jet engine sounds (-45dB).
The headphones stay comfortably in your ear. They don't always offer a complete seal but surprisingly, this doesn't affect noise cancellation or reduce comfort. Also included are 3 sizes of eartips to help better fit your ear. Note that these tips have a unique design so you won't be able to use aftermarket tips.
You can disable active noise canceling at a press of a button. Aware Mode can be quickly accessed from the remote, which will disable active noise-cancelling and open up the microphones to allow you to hear your surroundings better.
LEDs on the control module will let you know when this mode is turned on.
The suggested retail price for these headphones is $300. And although you can get a pair on Amazon for around $200 it still is a lot to pay for a pair of earbuds.
The highs are quite detailed, yet do not get harsh. The mids are slightly forward, so vocals and instruments can easily be heard. The bass is not very powerful but is tight, so you’ll get decent punch from your music.
You aren’t likely to have issues using these on the go. Most active noise cancelling in-ear headphones have large control modules, while the K391NC has a fairly compact and light module. You can easily use these headphones while walking and comfortably enjoy active noise cancelling with your music.
You can easily replace the 3.5mm cable should it get damaged. You can detach the 3.5mm cable from the control module which is very convenient. Other noise cancelling modules have fixed cables, so you’ll have to replace the headphones should the cable get damaged.
The accessories included are all very useful. You get two 3.5mm headphone cables, a USB charging cable, silicone ear tips, a travel pouch and an airplane adapter.
You’ll have minimal issues with headphone wires. While there is a cable connecting the earpieces to the active noise cancelling module, you can eliminate the need for a cable from the module to your source device if the source is Bluetooth capable.
These headphones can block out a decent amount of ambient noise. The active noise cancelling filters out most high and mid frequency noise. To further reduce low frequency noise, you’ll want to switch the eartips to the Comply foam ones.
Should the battery run out, you can still use these headphones in wired mode. There is a micro-USB to 3.5mm cable included so you can connect the ANC module to your source device. You won’t get active noise cancelling in this mode though.
The ANC module doubles as a remote, and gives you a lot of control over phone and music functions. There is a dedicated button for answering calls, a switch to turn ANC on or off, as well as buttons for volume adjustment and play/pause.
If you’re a bass-head, then these headphones may not be for you. While the low-end is present, it is not very powerful. Bass hits do not have a lot of punch and rumble.
The over-ear, closed back design allows for good sound isolation, minimizing sound leak while also minimizing the outside noise that can interfere with the music. This is further enhanced by active noise cancellation, which actively blocks out noise frequencies.
The i9BT has a V-shaped sound signature where the mids take a bit of a back seat in favor of the low and high frequencies. The bass is quite powerful so bass drum hits definitely have a lot of punch and depth. This is balanced out by highs that are very airy, bordering on harsh.
The powerful bass makes it great for bass heavy music like hip hop and dance. The overall V-shape sound however also makes these headphones a good pick for rock and pop genres.
Along with the fairly thick and high quality memory foam used on the head band and ear cups, the cushions' surface features real leather. Not only does this combination feel really soft, but is also quite smooth on the skin.
From a full charge, these headphones can give you 12 hours of playback when listening to music via Bluetooth along with active noise cancelling on. Playback time can last up to around 15 hours with noise cancelling off.
Some users hear hiss added to the music with active noise cancelling on. This can be distracting, especially if you are sensitive to these high frequencies.