Some time ago, I reviewed the Master & Dynamic MW08 Sport headphones. They were fantastic headphones, sounded great, had fantastic controls, and great battery life, but I couldn’t use them for phone calls. They had no way to bring audio from my speaking in, making it awkward to talk. It feels like having your ears plugged, and makes speaking on calls uncomfortable. I called them “My saddest return ever” because not being able to use them for calls was a dealbreaker. I got the Bang and Olufsen Beoplay EX headphones after that, a purchase I now regret due to persistent Bluetooth issues, lousy support, and only middling noise cancellation and transparency.
Master & Dynamic released the MW09 headphones, taking the best parts from the MW08 Sport headphones and making them better. Cooler styling (if that’s possible), improved sound quality, improved battery life, but best of all… sidetone. That’s what they call it when you can hear yourself speak. The one reason I couldn’t keep my MW08 Sport headphones had now been fixed.
They’re my new favorite headphones, but they’re still not perfect.
In This Article:
Specs
- Single Headphone Weight: 8.1g
- Case with Headphones Weight: 50.5g (Kevlar) 62.5g (Aluminum)
- Case Dimensions:
- Width: 64.5mm
- Height: 45.5mm
- Depth: 25.6mm
- Battery Life: Up to 48 hours with case, 16h without
- Bluetooth: 5.4, LE Audio Ready
- Drivers: 11mm beryllium drivers
- Water Resistance: IP54 headphones, IPX4 Case
- Wireless charging and fast charging
Sound Quality 9.5/10
I’m going to rave about the sound quality, but I’m not going to give it a 10/10. It’s a bit sad. If I had never tested the Bang and Olufsen Beoplay EX, I’d give this a 10. That’s why I gave the previous version of these headphones a 9.5 as well. However, now that I’ve tested these, well, the Beoplay EX would likely get a 9.5 too. The MW09 headphones aren’t better, they’re just different… in a way that makes them better and a little worse.
I swear, it makes sense.
The Bang & Olufsen Beoplay EX has a clean, almost reference-like sound. It’s detailed and crisp, with a lot of detail on the top end. It’s an incredible sound, and made me realize just how sad it is that the AirPods Pro, Apple’s best in-ear headphones, sound awful in comparison. However, the Master & Dynamic MW09 also sound incredible. They have detail, but it’s not focused on the top end. More in the mids, for sure. The entire sound signature is warm. These aren’t reference buds. If you’re looking for clean studio-mixed audio, these aren’t for you. You can tweak their sound to your liking with the in-app EQ, but all sounds will sound warm, and your attempts to remove that from the sound signature will just make them sound muddled.
Live Detail
These aren’t perfectly detailed. They’re detailed enough to certainly be in the upper echelon of Bluetooth in-ear headphones, but not the best. What they make up for is a sound that feels alive. It turns out, Master & Dynamic figured out they wanted to recreate a live sound. They succeeded. With the right tuning, you can really make these sing. They feel like a live performance, not a perfectly clean studio-mixed sound.
Coming from a clean sound, I wasn’t sure I liked these right away. But I tuned the equalizer, adding more volume and detail on the top end to help balance out what felt like, to me, a far too warm sound stock. Boosted some of the mid-bass and I had something that sounded magnificent for rock, R&B, folk, and even electronic. 3005 by Childish Gambino is enveloping, with rich dynamic sound. Bass thumps. While there’s less sub-bass, which I found becomes too muddled if I boost it too much on these, it’s still present. One of my favorite albums is Daft Punk’s Random Access Memories, which just sounds powerful coming through these headphones. Brandon Flower’s voice is a spark of brilliant light in The Killer’s Be Still. These have powerful and engaging sound, not balanced studio reproductions.
The MW09 have a warm sound, as Master & Dynamic intended. That limits how much you can modify the sound to your liking. In that sense they are more limited than more reference-like headphones. You can’t make these sound like other headphones, they’ll always sound a little warm. What you get is a powerful, energetic, live-like experience. If you believe music is best experienced live, with the thrill of the crowd and the bass in your chest, then these are the headphones that attempt to capture that mood. They do a fine job with the task despite their small size.
A Wide Stage for a Big Sound
In fact, outside of the warmth and energy they bring to music, one thing that surprised me was the sound stage. There’s an expansive enough sound stage in these that even when I go to other excellent-sounding headphones like my Beoplay EX, I suddenly realize that other headphones sound narrow, Like a small stage or a private studio session. With the MW09, you have space, you have a feel of a larger area. You can pinpoint where each sound comes from, and they’re a distance from you. It’s a large stage rather than a small room, and it gives that wonderful sound signature the stage it deserves. These complete that illusion of live music better than any other in-ear headphones I’ve ever used.
But it’s true, they’re not perfect. There’s a small amount of distortion, especially if you try to highlight the details in the sub-bass. They’re certainly not perfect. But if you just want to experience your music instead of analyze it, you certainly won’t mind. These are for feeling, not for analyzing.
Active Noise Cancellation 9/10
When I first put these on, I was surprised. I had forgotten what good ANC was like. The Beoplay EX headphones I had been using for the past few years had made me forget what it’s like for headphones to actually close out the world around you. I’d put these close to the ANC of the AirPods Pro, perhaps even a little better with the Max ANC settings turned on. They’re not as good as over-ears, like the AirPods Max, but they don’t disappoint.
In loud subway stations, I’d have to look around for visual cues to know the train was coming. Feel the vibration in my feet, the light change in the air. I’d notice all of that before I could see or hear the train. Of course, it’s not completely silenced, you can certainly hear it as it gets closer, but it’s a hell of a lot more tolerable than the other headphones I’ve been using.
ANC comes in three versions. They’re like different levels of noise cancellation. ANC records external sounds and creates sound waves of their opposite to cancel out those louder sounds. That takes more energy than just playing music. Higher levels of ANC use more power. That’s why Master & Dynamic features a two different levels, three options, for ANC. The first is “Max ANC.” This just cancels out as much external noise as these headphones are capable of. It uses the most power. Next is “All Day ANC.” This is ANC for quieter environments, such as an office, or at home. You can still let in louder sounds with this mode, giving you a little awareness back.
Then there’s adaptive ANC. This adjusts, using All Day ANC until noise levels reach a point where Max ANC should turn on.
My biggest complaint here is that they never seem to remember what mode I’ve selected and always go to Max ANC. All the levels work well, and I often can’t even tell when Adaptive ANC is choosing one level or another.
Ambient Listening (Transparency Mode) 8/10
Then there’s the opposite. Some brands would call this “transparency mode,” on the MW09 headphones, it’s “ambient listening.” These have three modes like the active noise cancellation, and there’s a large difference between them. The first is “Voice,” which, as you might expect, boosts the sounds of the voices around you, including your own. However, it also turns down other sounds a little. Not quite like noise cancellation, more like it’s only boosting voices, and you have things in your ears blocking out other sounds.
Next is “Natural.” This sounds like the world around you, just turned down slightly. It’s an across-the-board slight noise dampening. You might not notice it or think about it much if you aren’t paying attention to things around you. It’s likely best for times when you need to be aware, but don’t necessarily need to have a conversation.
Finally, there’s my favorite mode, “Awareness.” This boosts the sound around you slightly. It seems tuned on voices, specifically, but also passes through other sounds. It feels like it’s trying to amplify the sound slightly, and increases the pitch a little as a result. The best way to describe it is like hearing a recording with the volume turned up. It’s not completely natural sounding, but I like that it feels like it impairs my hearing and awareness of my surroundings the least. If you want to be able to hear a conversation, even watch TV, this is the mode to choose. It might not sound perfect, but it’s the closest to having nothing in your ears at all, volume-wise.
Sidetone 7/10
Along with both modes, there’s a specific feature called “Sidetone.” This is the feature I was waiting for. I returned my MW08 Sport headphones because they had no way of letting you hear your own voice as you were talking. This made them uncomfortable to use in phone calls. However, Sidetone fixes that. It listens to your own voice and pipes the audio in so you can hear how you sound to others on a call. It gets rid of that clogged ear feeling too, making talking much more natural.
Sidetone isn’t perfect, but it’s better than previous models and many headphones I’ve tried that either only have a transparency mode or do nothing to let you hear yourself talk. I’d put them below Apple’s AirPods with transparency mode, and even below my Beoplay EX headphones, which have the same feature. However, it works more than well enough that I can forget I have anything in my head. Given how much better these work in other ways, like ANC, I’d say the sacrifice of a little sidetone reduction is worth it. I don’t hear my voice echoing through my bones as much as I hear it as though my ears weren’t clogged up with headphones, and that’s all I needed.
Mic Quality 6/10
Sometimes, I’ll keep my headphones in when I’m recording a video. It keeps my voice clear, and, usually, you can hear the keyboard or anything else I’m showing off. However, with these, I was surprised to find this wasn’t possible. The firmware in the headphones automatically blocks off background noises. It defines just about everything that isn’t your voice as a “background noise.” I can point my desk fan directly at my head, clack away on my noisiest keyboard, squeak in my loud computer desk chair, none of it’s getting through. These really only care about your voice, and there’s no way to turn that off. I woulde have liked a way to turn it off for recording normal audio.
I have found that you can mess it up with distortion in your voice. I did the thing that every child and most adults will do, given the opportunity and proximity to a fan. Yes, I told Luke I was his father. I talked through the fan quite a few ways, using a variety of voices (my robot voice? Top notch!), and none of them got picked up. I sat there recording my voice for about a minute, and it barely showed any sound in my recording. Loud noises and distortion could make these not pick up your voice. Any change in what might be normal human speech is enough to make it disregard what you’re saying.
There’s another side to that, of course. It means your voice shines through loud and clear with traffic, city noise, a desk fan, a loud AC unit, anything. Your voice will shine through on calls. There’s a small amount of compression in the voice, that sort of “phone sound” that people know and don’t realize is compression, however it’s not bad. Voices are recognizable, but you’re not going to use these for singing. I’d recommend a better mic for that. For everyday conversations or the occasional FaceTime “Happy Birthday” song, you’ll be fine.
Battery Life 10/10
I do love it when I can better describe a device’s battery life in days rather than hours. You may find you need to charge these every four to five days. If you listen for more than 8 hours a day, maybe you’ll have to charge twice a week, but most weeks you’ll only need to charge these to 100% once a week.
The buds themselves can last up to 16 hours. Apple introduced Beats that last 18 hours on their own, and that’s impressive, but Apple’s Beats headphones aren’t backed up by a case that can add as much as 32 hours on its own too. These could easily last 48 hours on a single charge. That’s two full days of listening, and you’re likely not going to be listening to them that much. Easily you can get 3-4 days, likely loser to 5-6 days, of battery life out of these. Charging once, maybe twice a week, it’s a beautiful thing.
In my own tests, usually with Max ANC turned on, I saw between 30-40 hours of battery life. Not quite the maximum that they claimed, but I am also using the battery draining Max ANC. Master & Dynamic lets you turn this off if you need to, and you can even use battery saving versions of their features that can prevent battery life drain. Still, at their minimum, with me burning through the battery as fast as I could, they lasted far longer than any other truly wireless earbuds I’ve used.
Connectivity 6/10
I’m a software engineer. I know what a pain in the ass Bluetooth is. Latency issues, dropped packets, unreliable connections, it’s an absolute nightmare. Bluetooth LE’s improved range and energy consumption has improved connection reliability, but it’s not perfect. These are “LE Audio Ready.” If you have a device that supports Bluetooth 5.4 or LE Audio, you will notice an improved connection. Even as I connect these to both my iPhone and my MacBook, I’ve noticed they’re more reliable than my Bang & Olufsen headphones doing the same.
Better, but not perfect.
I noticed it gets less interference from having two devices playing sound, but some apps are still problematic. Auto-playing videos on Instagram still sometimes interrupt a video I’m watching on my computer. I’ll usually be able to stop it by quitting the app on my phone or re-syncing the headphones by putting them in the case and then taking them back out. I also found that doing a factory reset helps if all else fails, but this has been a last resort I’ve only had to do twice in the months I’ve owned them. In comparison, my Bang and Olufsen headphones never work when this happens.
I also noticed that when I have multiple Bluetooth devices active in an area at once, I can have interference. When my AirPods Max are on, my Bluetooth trackball mouse is on, and these are trying to play sound, I may get some cracking and each side dropping out randomly.
Finally, I noticed these issues more frequently when I connect them to three or more devices. Something about having the connections in memory and checking them for a reconnection attempt, perhaps.
Bluetooth is far from perfect, and multipoint Bluetooth is still a mess. The only devices I haven’t had problems like this with are ones that don’t have multipoint. However, of the devices that I have tested with multipoint, these have performed the best. A low bar, but they cleared it. Mostly.
Controls 8.5/10
Touch surfaces, touch screens, they’re all well and good. But my ears can’t see that well. That means I have to touch items to figure out where they are. I can rely on muscle memory and their feeling in my ear only so far. I prefer a button I can feel, not one that will do something I don’t want it doing if I bump it. The designers at Master & Dynamic seem to agree. These headphones have actual buttons. Real controls. Perfect for operating your headphones when they rest in your ears, out of sight. I got so used to my Beoplay headphones reacting to the slightest touch that I’d be careful adjusting my hair, or these headphones in my ears. Only, I’d then realize they only operate when I actually ask them to. On the right side is the standard action button. Play/pause, Siri and voice control, skip controls, that sort of thing. On the left is a volume rocker. Press and hold volume up to open yo your ears to the outside world, turning on ambient listening mode. Go the other way for active noise cancellation.
I love these. I wish every set of headphones had physical controls. The only ones I’ve used that didn’t have physical controls that were okay were the AirPods Pros, which have a force-sensitive stem you can squeeze to activate. That’s almost like a button. Unlike most headphones, you won’t have to worry about the controls, these work exactly as expected. They’re easy to use too.
Now the one issue with the controls, and it’s a doozy. Changing between modes takes three seconds. That may not seem like very much, but three seconds is a long time to be holding your finger down on a tiny button, trying to remember if forward or backward is the one you were looking for. Plus, I’m an impatient person. I watch videos at 3x speed! I cannot do 3s. At least make it adjustable! This should be around 1 second, at most. By three, it’s a chore.
Charging 8/10
One thing I didn’t see on the product page—because it isn’t there—is that the charging case is magnetic. It has two curved magnets on the back that perfectly align with a Qi2 charger or MagSafe charger. That’s right, this charging case can stick to your MagSafe chargers as well as your iPhone can! It was such a lovely surprise. I could just plop it down on one of my MagSafe chargers and forget it, perfect!
Well, almost perfect. It gets hot when charging wirelessly. Especially the hinge on the back of the case. Not quite leaving burns hot, but definitely, “What were they thinking?” hot. They certainly should have limited wireless charging more, this feels dangerous, and it’ll drain your total battery capacity quickly. My suggestion? Only charge these with wireless when it’s going to be a quick top-off, just for a few minutes before leaving when your battery’s low, that kind of thing, not for the hours it would take to charge from empty.
Of course, all that heat comes from it accepting fast charging. According to Master & Dynamic, it can charge your headphones enough for 2 hours of listening in just 5 minutes, when done with a USB-C cable. 20 minutes can get you to 50%, with 100% taking about an hour of charging with a cable, just over three hours if doing it wirelessly. For how slow wireless charging is compared to wired, consider it for when you’re in a hurry or can’t find a charger. Slower charging with a cable will be best for battery longevity, but it’s good to also have the fast charging option, even if I wouldn’t recommend using it every time.
Appearance 10/10
I don’t know if there are better looking earbuds on the market. The new design with a raised circular area containing the sapphire glass, and aluminum together look fantastic. I’ll admit, if the raised portion had speaker grille, it would look cooler, like it either has open back features or a microphone array, but it’s not necessary. The new design does make it feel more in-line with their other headphones that do have those design elements.
My only criticism? God, this would look so cool in ruby red. Why do they continue to deny us a ruby red color? It’s all dark tones and muted, more masculine colors with these people. Give me a lilac one, a red one, yellow and orange. Sure, there’s silver, that’s… okay. But if you want the tougher, easier to grip kevlar case, you don’t get the prettier options. The green ones are nice, they definitely are. I love the way these look. But a little bit of variety here wouldn’t kill them!
Fit/Comfort 9/10
I had some trouble getting these just right. I always do with headphones. I feel like I have weird ears, because I’ve never gotten new headphones and didn’t have to try 10 different tips on them before I found one I liked enough to stick with. I ended up going with Spinfit, but even then, the first ones I got were too small and kept them from hitting the back of my ear and locking in. Eventually I found the right size ear tip, width and length, to secure these comfortably in my ears. Once you do, they’re easy to forget about.
Yes, they’re heavier than most headphones. They have aluminum and sapphire construction, and more battery life than most headphones you’ll use, of course they’re a bit heavier. But it’s not really noticeable. You might have a higher chance of shaking them loose while exercising, but the foam tips or a large tip may secure that better. I haven’t had an issue running up and down subway stairs or dancing like an idiot in my apartment. They secure comfortably, and I think most people will be able to find a comfortable fit. It’s not as easy as I’ve had with the AirPods Pro, which may be the most comfortable headphones I’ve tried, but they do stay in better, and bring a lot more to the table than the AirPods Pro when it comes to sound quality, style, and battery life.
Sustainability 6/10
The packaging is cardboard, through and through. Master & Dynamic was even careful to reduce the amount of dye they used. It’s a nice and reusable cardboard container, storing the different ear tips, instructions, and anything else you’d like to include in there. However, they made the terrible decision of wrapping the entire thing in a thin plastic overwrap. They could have used a sticker, a cardboard seal, a small bit of glue, anything would have been better than choking all that nice cardboard with plastic. They came so close to having the perfect packaging, only to fail at the overwrap.
Besides that, this battery case holds enough battery life to last you through most of your week. Even heavy listeners will be able to make it a few days. That’s many times better than what you’d get from most headphone manufacturers. As a result, you’ll find this battery life tolerable for a long time. That means fewer replacements, keeping these in your ears for many years. By the time you upgrade, it likely will be due to new features in a new model or losing them, not because the battery life has become intolerable. In comparison, my AirPods Pro and Beoplay EX headphones have terrible battery life from the factory, making them annoying and constantly on a charger two years after purchase.
Charging Case 9/10
Some other notes worth mentioning about that charging case before we wrap up. The design is, well, I suppose it depends on how you think about kevlar. I’m not a fan of it. However, it’s tough, it’s durable, and it feels nice in the hand. It has a softness to it, along with grip, while still feeling smooth. It’s not quite as grippy as silicone, but it does have some grip to it. I almost never drop it. Compared to headphone cases made of aluminum and plastic, it’s been great. So, sure, it has a jagged design that’s come to be popular with the obnoxious kind of people you might find online if you just made a new YouTube or TikTok account and watched a video about WW2. But it’s small, has great battery life, and it’s texture makes it easy to hold. Forget what you know about kevlar, it works well for this.
I love the charging indicator lights on this case. Rather than a single LED, there are three. In normal settings, there’s one for each headphone and one for the case. Sometimes, when using the microphone a lot, you might end up with one headphone having lower battery life than another. But that’s not the only reason it’s useful. Three lights, each able to display one of three colors, means you have far more options for error codes and other statuses. You don’t have to figure out if it’s blinking fast or slow, or if red orange is an error or low charge. It’s a lot easier to tell when it’s not quite on the charger just right thanks to those lights. It’s a little thing, but one of those little things that just makes this better than any other headphone case I’ve used.
Also, due to the headphones not having stems, the case itself is easy enough to clean with some rubbing alcohol and a paper towel. Maybe a pointed Q-tip for the headphones themselves, but the rest is incredibly easy to clean. You should absolutely be cleaning your headphones on occasion, and this will make it easier to avoid ear infections.
Overall 9/10
I am so passionate about music. I get lost in it, tear up from a beautiful vocal performance, dance my heart out at concerts and in my living room alike. I love music. These headphones, more than most I’ve tried, remind me of that love. These were made people who love music for what it does for humanity, not strictly for technical qualities. Hearing Brandon Flowers’ voice cut through the music in The Killer’s Be Still is just breathtaking. I’ll get chills. As I had both my headphones in, my MW09 and Beoplay EX headphones in each ear, it was the MW09 that I gravitated to. It was there that I could feel the soul of music. My Beoplay EX headphones were recreating the song. The MW09 headphones made me feel like I was there. The depth, the warmth, the sound stage. It just makes music come alive.
There are plenty of headphones out there that could serve as a reference. Perfectly replicated music. But there’s a reason vinyl survives. Why no VR headset and headphones will ever replicate feeling a singer’s voice blasting from speakers that rattle in your chest (wear ear plugs, people). These headphones get the closest to the raw, real music that brings tears to eyes and sends chills down your arm. Is it as accurate as my Beoplay EX headphones? No. But it’s visceral, warm, real. It’s the difference between a guitarist who tunes with an electrical meter and another who uses their ear. The person voraciously sniffing their wine to convince themselves they know the difference from a Franzia and a French wine and the person who prefers clinking glasses with their friends, regardless of the contents. You want an excel spreadsheet as headphones, perfectly measured and calculated? Then maybe the MW09s won’t be for you. But if you want to remember why you love music, these are the ones to listen to. Master and Dynamic’s MW09s aren’t the perfect headphones, but damn are they better for it.