Master & Dynamic MW09 True Wireless ANC Earphones: Review

There are few consumer A/V categories as competitive as the true wireless earphones market and whilst only a handful of products control a huge slice of the market, there is still room for innovative products from high-end brands to earn market share. One of the most surprising models from 2021 were the Master & Dynamic MW08 TWS which faced a mountain of competition from Apple, Sony, Bose, Bowers & Wilkins, and Sennheiser.

The MW08 TWS proved to be superior in many respects, but the product cycle is rather short and none of the models that we compared to the MW08 TWS are still on the market. The new Master & Dynamic MW09 TWS face some rather stiff competition in 2024 and we wanted to see if they could pull off another miracle.

Build Quality

Master & Dynamic are a boutique premium brand and buyers expect higher quality materials and better design than one would find in more mass market products; the MW09 also retails for at least $50 more than the MW08, which means that expectations should be higher.

The good news is that fit and construction materials live up to that expectation whilst the packaging shows Master & Dynamic’s commitment to using recycled materials wherever possible.  

Other than the white slipcover, all of the packaging is recycled material including the tip holder and the wrap around the charging cable. The kit contains the earpieces, charging case, 5 silicone tip sizes, 2 sets of foam tips and a USB Type-C charging cable.

The cases come in two styles; either aluminum or Kevlar/carbon fiber with the later adding $50 to the $349 base price. 

Finish options include gold/gold, black/black, and silver/white in the aluminum case or blue, green, and gunmetal earpieces in the Kevlar case.

Design

The earpieces are similar to the MW08 with a square (ish) outer face and a molded portion that fits in the ear beneath it. The face is a mix of sapphire glass and aluminum with a large circle sporting the M&D branding in the center.

There is no plastic to be found on the earpieces which helps them not only look better, but should make them more durable as well. We like the large button controls on the upper side of the face instead of having to learn yet another pattern of swipes.

It’s a simple and robust control system and much less prone to misinterpretation than some of the touch sensor models.

With 5 sets of silicone tips, most users will be able to find a good fit among the options. I did find they run a bit smaller as the ‘ML’ was a better fit for me than my usual Medium-sized tip.

The foam tips only come in one size, but sealed well and should prove to be useful when in high noise environments where the extra isolation is needed.

One thing to note is that the foam tips changed the signature, so be aware that you may want to use the EQ to correct back to the stock presentation that is less bass heavy.

Charging Case

The charging case shell was manufactured from aluminum on my review set with a glass rear panel that matches the face plates of the earpieces. The rear plate stands out as the aluminum features matte black anodizing while the glass is quite high gloss.

There are 3 LED indicators on the face just below the junction with the lid that show charge state for the case (center) and each earpiece (L/R).

The USB Type-C charge port is on the right end of the case just above the base and allows the case to sit upright and open while charging which is another ergonomic touch that more manufacturers need to adapt.

We hate cases that can’t sit upright and charge with the case open; it feels like a lazy design choice when it happens and really does not make sense in the current market.

We also appreciate that the case fits neatly in a pocket while still providing enough charge time to be worth carrying. 

The earpieces themselves have a claimed battery life of up to 16 hours (more on that in a bit) with the case adding another 2 full charges. This is another trade-off that a surprisingly large number wireless IEMs struggle with; models that offer a longer battery life but feel like a brick and those with smaller batteries as a way of saving weight, offer inferior battery performance.

For those looking for something even lighter, the Kevlar case shaves 12.5 grams off the weight but retains the size and charge capacity of the aluminum version.

What’s New?

Master & Dynamic stuck with the MW07 series models for quite a while before releasing the MW08, so the MW09 designates another large step as something more modest would likely have been branded the MW08+.

Is there anything that different about the new MW09 TWS?

Externally, the new MW09 earpieces are about a gram lighter but retain the IP54 rating previously seen on the sport models and the case now sports an IPX4 rating, so whilst not waterproof, should survive a spilled drink on the desk.

Wireless charging of the case is another nice feature which first arrived on the MW08 Sport but was not a feature of the original MW08.

Internally, the drivers remain the same 11mm beryllium coated dynamic driver, but nearly everything around the driver has been updated. 

Battery life has been extended, ANC has been upgraded, the microphones used for calls and ANC are now backed by an AI noise reduction technology, and Bluetooth has been upgraded to 5.4 with LE Audio and aptX Lossless support.  

Support for aptX Adaptive, AAC, and SBC are still there as well for those with phones that lack support for the newer standards; which is the vast majority of smart phones that are for sale.

It would be fair to characterise the MW09 as a blend of the MW08 and MW08 Sport model.

Class Leading Battery 

We run our fatigue, battery life, and listening tests during the same session, but the battery performance was so impressive that we had to stop; my ears gave out before the MW09 ran out of juice and that would have been foolish behaviour on my part to push any further.

We averaged slightly over 14 hours with disengaged. With adaptive ANC, it was still in the 10 hour range and the case worked as advertised, providing an additional 2 full charges and 2 hours of listening from a quick 10 minute boost.

This meant that our battery tests had to be conducted in 4 hour blocks and there is no question that we had some loss of charge with the earpieces disconnected but not in the case during the intermission.

The MW09 TWS offer superior battery performance and have to be considered the class leader in that regard.

Sound Quality

With the same 11mm beryllium coated dynamic driver with neodymium magnets and an ultra-light voice coil, one might expect the sound of the MW09 to remain the same as previous models, but it has its own unique signature that is a bit warmer and slightly bass forward compared to the MW08.  

Some will appreciate that extra bass push while others will experiment with the pre-sets and custom EQ settings to create the signature that appeals the most to them. 

The “audiophile” mode was my preference in terms of tonal balance, but all testing was conducted with the MW09 TWS in their most neutral setting.

Sub bass has more emphasis than the MW08 with good depth but limited texture as you descend further down into the range. Texture improves as the frequency moves up and the mid bass sports good texture overall; my biggest complaint would be that it could use better definition overall.

The stock low end was slightly warmer and more robust sounding than the MW08; compared to the MW08 that came across as more linear sounding and with less impact. The MW08’s bass performance was certainly cleaner sounding than the MW09 and the use of EQ felt somewhat necessary in the range.

The MW09 responded to EQ well and a judicious reduction in the lower frequencies brought it right back to the clarity of the MW08, but with a bit of extra impact that the MW08 couldn’t deliver with the same authority.  

The best feature of the low-end is its response to EQ as the audiophile pre-set helps level it out and the bass-cut setting will be something treble lovers will enjoy.

Using the ‘Neutral’ sounding created a better sense of balance in the bass range.

The lower midrange offers good weight and a bit of warmth that helps male voices sound full and rich. The warmth yields a bit as the signature moves into the true midrange and guitar has enough rasp and edge to sound realistic and strings have good energy and clarity. 

The upper midrange exhibits a mild lift as it moves into the lower treble that pushes female voices a touch forward in the mix and helps them stand out.  

Overall, it is a good listen for popular genres with the default tuning and can be improved for classical or jazz with the EQ settings.

The lower treble features some additional emphasis but it never makes the overall presentation overly fatiguing; nobody could find the MW09 to be strident sounding in the treble range.

The result is good percussion snap and cymbals that sound almost real. We could use a touch more energy here for shimmer as hi-hat energy and detail isn’t quite fully delivered.  

Above about 5 kHz, the MW09 drops back to the same level as the midrange which makes the treble range generally rather even sounding.

The upside is long listening sessions don’t become fatiguing; the downside being limited air and sparkle at the top.

We found the driver to be less responsive to EQ in the upper range, so whilst the treble can be brought further forward in the mix, it is more a matter of reducing other frequencies to let the treble shine through, rather than boosting the output in this region.

We don’t expect a large soundstage from small, closed-back ANC IEMs and the MW09 does show a limited stage size as expected, however what stage is present is well proportioned with only slightly more width than depth, and some sense of height.  

Layering is acceptable with the default tuning and comes into its own with the audiophile or custom EQ cutting back a bit of the lows to increase clarity.  

Imaging is also dependent on the settings and can range from passable to good depending on how much of the warmth and bass emphasis is scaled back.

Dynamic performance is relatively strong and that will appeal to those who want a pair of wireless IEMs with some impact and drive. The MW09 are most certainly not designed for those looking to do studio work when it comes to neutrality from top to bottom.

Noise Cancellation

ANC has been improved with a new Adaptive mode in addition to Max ANC, and All day ANC modes. Likewise, Ambient mode has 3 sub-categories; voice, natural, and awareness.

Max ANC does an admirable job of cutting out most droning noises but does boost some of the lows, so a more aggressive EQ needs to be used when using Max ANC.

Try setting EQ to bass-cut and ANC to max and it more or less reverts the signature to default, but with a decrease in dynamics.

For me, the all-day ANC was a good middle ground with better dynamics and less signature impact than the Max setting while still removing most outside noises.

Adaptive has the least amount of impact on the sound quality, but also does sometimes have trouble removing sudden noises as it simply doesn’t have time to adapt in those situations. 

In a steady environment, the adaptive function is nice as it conserves battery and provides enough noise reduction to be useful. In a rapidly changing environment, the ‘all-day’ mode is the better option.

Transparent Mode

The ambient modes do allow some outside noises to cut through, but don’t boost those outside noises to the level of the music, so are only viable if music is kept at background level.

Again this is not unusual, but many expect to turn music up to 80dB and still hear voices when ambient mode is enabled; this won’t happen regardless of setting but if listening at lower levels, the ‘voice’ setting does allow people in the immediate area to be heard, although I found the ‘awareness’ setting to provide the best clarity when wanting to hear external noises.

The App

The app, much like the button controls is simple and well laid out with most operations requiring no more than 2 or 3 clicks. The control app does require that the MW09 be paired first and they did go immediately into pairing mode when first removed but sometimes required that the buttons be depressed and held to return to pairing mode after original pairing.

I do have a OnePlus phone that supports aptX Lossless and the sound quality is notably better with lossless or adaptive when compared with SBC or AAC, so those with smart phones that support it will want to make sure Bluetooth is configured on the phone to take advantage of it.

Final Thoughts

With so much competition, the MW09 had to be very good in a number of areas to create a strong case for itself.

The battery performance is category leading and that will matter to a lot of users.

The controls are simple to use and straight forward; the learning curve is very short with these.

The tuning options are extremely useful and most certainly made a difference; the signature will appeal to bass lovers but will need a bit of EQ for those that prefer a more balanced signature.

Once tuned, the MW09 has good dynamic capabilities and was a fun listen with most genres of music.

This is not a studio headphone and won’t fill that role; it is instead a great option for those looking for a casual listening wireless IEM that provides enough ANC to be usable on mass-transit, good sound quality to be engaging, and enough battery performance to outlast your longest listening session.

Those looking for a pair of wireless IEMs that will outlast them on marathon flights (or while marathon running for that matter) need look no further than the MW09 that can provide a realistic 5 to 6 days of listening time without having to recharge the case.

ANC performance is quite good, and we would rate it slightly behind Sony, Bose, and Sennheiser. If ANC performance is the most important feature for you, the MW09 might not be your top pick.

If sound quality, build quality, battery life, and tuning options are more important to you — these need to be on your audition list.

We would still advise using some EQ to create a sonic signature that will offer a more balanced sound; which will certainly be effective at reducing listening fatigue if you plan on using these for many hours each day.

Where to buy: $349 / $399 at masterdynamic.com (depending on color)