Marshall Monitor III ANC review: A worthy alternative to Sony and Bose?

With a campaign fronted by Green Day’s Billie Joe Armstrong, the Marshall Monitor III ANC have made a splash in the wireless headphone market. I brought the Marshall Monitor III ANC with me on a trip to CES 2025 to find out how these headphones hold up as a daily driver. Of course, we also put the Marshall Monitor III ANC through our SoundGuys testing lab to get some objective data. Let’s find out if these headphones deserve a spot on your head.

What’s it like to use the Marshall Monitor III ANC?

The Marshall Monitor III ANC retain the classic amp design that makes Marshall products stand out on a shelf. The metalheads in your life will instantly recognize the aesthetic, while everyone else will appreciate that the headphones look and feel more premium than the plethora of sub-$100 headphones flooding the market. The hardcover carrying case with a red velvet interior is a nice touch, allowing me to easily toss the headphones in my carry-on bag. The small pouch inside the case makes it easy to store the charging cable, as well as the 3.5mm to USB-C audio cable, which I used to work on music and video editing over a wired connection while traveling.

At only 250g, the Marshall Monitor III ANC are lightweight, and I didn’t notice any pressure points on my head or ears. The ear cushions are extremely soft, and I’ve had no problems wearing the headphones on a three-hour plane ride, or even throughout an entire eight-hour workday. Like most over-ear style headphones, the Marshall Monitor III ANC do not have an IP water resistance rating, so best to avoid using them at the gym or out in the rain.

Should you use the Marshall app for the Marshall Monitor III ANC?

Like all flagship wireless headphones, the Marshall Monitor III ANC aims to differentiate with its unique set of features. To access all of the features, you need to download the Marshall app, which allows you to install the latest firmware updates. Once set up, you can view the headphones’ remaining battery life, switch between noise control modes, and adjust the equalizer. The custom equalizer provides five bands to adjust, or you can select from one of the five EQ presets. In the EQ section, you’ll also find a toggle to enable Adaptive Loudness mode, which dynamically adjusts the EQ based on playback volume (see equal loudness curves).

If you like spatial audio, you can try out the Soundstage mode. It lets you choose between four simulated room sizes (small, medium, large, and extra large) to place your audio in. There’s also a slider to adjust the intensity of the effect. To my ears, this just sounds like slapping a reverb effect on top of the track rather than a true immersive audio listening experience.

How do the Marshall Monitor III ANC connect?

You can connect to the Marshall Monitor III ANC headphones over a wired connection using the USB-C input. There is no 3.5mm auxiliary input, but Marshall includes a USB-C to 3.5mm cable in the box. The support for latency-free wired listening is a big plus for content creators when compared to headphones that don’t support wired playback like the Apple AirPods Max.

For wireless listening, the Marshall Monitor III ANC have Bluetooth 5.3 with support for SBC and AAC. Android users will be disappointed by the absence of higher-quality Bluetooth codecs such as aptX or LDAC.

How long do the Marshall Monitor III ANC’s battery last?

Marshall says you can get up to 70 hours of battery life with ANC enabled. Without using noise canceling, the headphones are rated for up to 100 hours of battery life. That is an exceptionally long battery life, and roughly double what see from comparable noise canceling headphones.

To extend the lifespan of the headphones, you can check out the battery preservation section of the Marshall app. This allows you to enable three different ways to preserve the battery life. The first is to limit the maximum charge to 90%. The second is to limit the maximum charging speed. Finally, you can have the headphones automatically lower the charging speed if the temperature is outside the ideal range. If you’re going to spend this much on headphones, it’s nice to know that they’ll last longer than a few years.

How well do the Marshall Monitor III ANC cancel noise?

The padded ear cushions provide excellent passive isolation against high-frequency noise. Enable noise canceling, and the Marshall Monitor III ANC will also block out roughly 20dB of low and mid-frequency noise. All told, this means the headphones reduce the loudness of external noise by an average of 83%. While this is less than the 88% reduction in noise we measured on the AirPods Max, it’s about average for modern noise canceling headphones.

If you don’t like the feeling of strong ANC, you can also decrease the strength of the noise canceling within the Marshall app. Alternatively, if you like to stay aware of your surroundings, you can choose from three different levels of transparency mode. At its highest setting, the transparency mode amplifies surrounding noise louder than when you aren’t wearing the headphones at all.

How do the Marshall Monitor III ANC sound?

The Marshall Monitor III ANC deliver good sound quality that will please most listeners. These aren’t my favorite-sounding wireless headphones on the market, but I also didn’t mind using them while traveling.

Multi-Dimensional Audio Quality Scores (MDAQS)

The chart below shows how the sound of the Marshall Monitor III ANC was assessed by the Multi-Dimensional Audio Quality Score (MDAQS) algorithm from HEAD acoustics.

The default tuning of the Marshall Monitor III ANC will please most casual listeners, given the exceptional Timbre score of 4.8 on a scale from 1-5. On the other hand, simulated listeners rate the Distortion and Immersiveness as just okay, with respective scores of 3.1 and 3.8. An Overall score of 4.4 means that most people will enjoy the sound quality of the Marshall Monitor III ANC.

Reviewer’s notes

Editor’s note: this review uses a hover-enabled glossary to describe sound quality based on a consensus vocabulary. You can read about it here.

Objective Measurements

Compared to our industry-validated SoundGuys Preference Curve, the default sound of the Marshall Monitor III ANC has more bass, less mids, and more treble. The five-band equalizer in the Marshall app gives you some room to tweak this, but you can’t dial in the exact frequencies you want.

Can you use the Marshall Monitor III ANC for phone calls?

The Marshall Monitor III ANC headphones have microphones that you can use for taking calls on the go, but I wouldn’t rely on them for frequent use in important meetings. In our microphone samples below, you can hear that the microphones do a good job of blocking out background noise, but they struggle with vocal clarity. Additionally, the microphones clip at a high volume input, which could be a problem if you have a loud voice.

Marshall Monitor III ANC microphone demo (Ideal conditions):

Should you buy the Marshall Monitor III ANC?

The Marshall Monitor III ANC are by most measures good headphones, but I wish their price tag wasn’t quite so high. At this range, Marshall is competing with flagship headphones from the likes of Sony, Bose, and Sonos. While the Marshall Monitor III ANC sound good and have decent noise canceling, they don’t quite have the features or performance to stand out as the best wireless headphones on the market. With their connection versatility, long battery life, and great carrying case, I enjoyed using the Marshall Monitor III ANC on the road, but they won’t be the first headphones I reach for in the future. That said, if you can find the Marshall Monitor III ANC on sale for less than $300, don’t hesitate for a second to buy these headphones.

What should you get instead of the Marshall Monitor III ANC?

If you are looking for travel headphones, the current best option on the market is the Bose QuietComfort Ultra Headphones ($429 at Amazon). While these may run you a bit more money than the Marshall Monitor III ANC, you can frequently find them on sale since they debuted back in 2023. The Bose headphones are exceptionally comfortable, have great noise canceling, and good sound quality with support for aptX Lossless.

Of course, you can’t talk about wireless headphones without mentioning Sony. While we hope to see the WH-1000XM6 headphones soon, for now you can try nabbing the Sony WH-1000XM5 headphones on sale ($387 at Amazon).

On the other hand, if you have an iPhone and a big enough budget, you should consider the AirPods Max ($499 at Amazon). These headphones might be half a decade old, but they still deliver great sound quality and best-in-class noise canceling, according to our measurements.

Marshall Monitor III ANC review: FAQs