Headphones

I just received these today. Let me just first say, they were extremely easy to pair via Bluetooth to both my iPhone and with my Lenovo laptop on the first attempt (no apps, no troubleshooting, just plug-and-play and both earbuds worked with the laptop, which was always an issue for my old Bose earbuds). However, I wasn't able to switch between devices quickly and had to fully disconnect them then reconnect to a different device. I also didn't really have any issues when putting the right ear bud away and switching to a single bud or back to dual.

The fit is pretty comfy, but took some getting used to, initially they feel like they're going to fall out, but they actually stay snug and they're even smaller than I anticipated. But after a couple of hours these standard rubber fittings start to get a bit uncomfortable.

As for the sound quality... I have mixed reviews. When paired with my iPhone, the sound is actually pretty solid, it's clear, crisp and pretty clean. There's the slightest bit of an echo and it feels a bit muted or muffled; but still far better than other earbuds I've tried. The range is impressive with sufficient bass, and it's a true stereo experience, although I found the max volume tops out rather quickly but is generally sufficient, particularly with the noise-cancellation on. Unfortunately when paired with my laptop, there was a distinctly different sound, which was highly muffled, pretty low quality and far less enjoyable. My gut reaction is that these were designed with the iPhone in mind and there may be differences in codec, which makes me wonder how these would perform when paired with an Android phone (hopefully other reviewers can weigh-in on this). I also happened to simultaneously purchase a set of the KEF M100 wired earphones (which indicate "Made for iPhone") for work/travel and as a backup in case I run out of battery. The M100's sound simply amazing on my laptop and perform even better than the Mu3 when connected to my iPhone, presenting with greater depth and crisper tones, so I know the issue is not the audio source. Full disclosure, I also own a pair of KEF LS50 Wireless II bookshelf speakers which are simply amazing (and the main reason I decided to try-out these KEF earbuds).

The noise-cancellation is pretty darn good, it will definitely block-out any low-volume or moderate ambient noise, I also like that it's very easy to switch from ANC back to the ambient setting. I haven't yet tested it on any phone calls. And although I like that the controls are simple and no frills, I don't love the volume control which requires a long press and takes a few seconds to engage. The quickstart guide wasn't entirely intuitive at first (like a long press on the right/left buds results in volume controls +/- respectively). Note that the left ear has ANC and volume control, and right ear is, play/pause, volume, and a double-tap = next track.

In summary: Overall, I'm really happy with these earbuds. They deliver excellent sound at a reasonable price, solid noise-cancellation, good fit and low profile, all with superior battery life.

Pros:
- great value (on black friday sale), nothing else delivers like these at this price point
- easy to connect to a single device
- sounds fantastic with iPhone/Apple devices
- comfortable and smaller than anticipated w/relatively low profile
- excellent battery life of 9 hrs posted (not yet tested, but almost 2x my old Bose)
- relatively simple controls

Cons:
- non-iPhone audio inputs seem to deliver inconsistent/muffled sound
- unable to switch between different devices quickly
- volume controls require a long hold/press and take about 2-3 seconds to engage, which often result in inadvertently pausing or advancing tracks on the right earbud

KEF really delivered with this. The promise of neutral sounds was not some excuse for underperformance. I've heard things in music that I've known for decades that I'd never heard before - even those I've listened to on pricey over ear headphones. The clarity, perfect amount of treble, bass and mids made me want to go through my entire library of music again. Other speakers or headphones gave me listener fatigue, but this lets me listen for hours and hours. Not to mention how comfortable they are to wear. Noise cancellation is sufficient for me, even in a noisy train. I didn't buy these for calls. I was looking for the best possible music reproduction in wireless headphones, and I'm really happy with them.

In this price range these are the best that I have heard. Neutral with buoyant bass. Like the other reviewer these fit my ears like a glove. Highly recommended.

Great sense of audiophile detail in the music, decent bass, and very good mid-range. I would have loved to have some type of control with the coupling of some type of software. In addition to these IEM being very comfortable, they fit my ears perfectly. Overall I am very pleased with the quality of the sound these IEM bring out in my music...