Marshall Monitor III destroys all other headphones with its indomitable 70-hour battery life

Marshall upgraded the Marshall Monitor III ANC headphones in some key areas, making it a significant improvement over the Monitor II released way back in 2020. I have been testing the Monitor III for almost nine months now, and my love for them has only intensified.

I had the opportunity to sit down and chat with the lovely team behind the redesign, and it gave me a deeper understanding of just why the Monitor III headphones are so much better than the older iteration.

Better in every way, shape, and form

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While the redesign isn't a dramatic rethink, it looks a lot more modern and streamlined now. The Marshall Monitor III wireless headphones are made out of recycled aluminum, silicon, and other materials. The engineers prioritized durability and performance without compromising sound quality and comfort.

The Marshall Monitor III headphones are the most compact pair on the market. You can twist and contort them to fit into the egg-like carrying case, which is made of leather and lined with luxurious red velvet. I found this size ideal for traveling as the case fitted into my carry-on very easily.

The earcups are as soft as marshmallows. I have several piercings, and most headphones often don't sit well, pinching me and irritating my piercings. These cups don't do that, which is a welcome change. This wasn't an accident; Marshall tested with glasses, earrings, and a variety of other variables to ensure a comfortable wear experience.

These removable cups are made of 40% soft foam and 60% slightly denser foam with springs coiled behind the ears. These cushion ears and, at the same time, efficiently block out sound.

Marshall used this to improve active noise cancellation, as well as newer, more optimised mics. The ANC is adjustable within the Marshall app, and there's a dedicated ANC button to switch modes as well.

A win for durability and repairability

I love the fact that the Marshall team focused on durability and repairability, so users will be able to hang on to their Monitor III headphones for a very long time. The brand assured me that each crucial component of the headphones can be replaced within 10 minutes.

They even redesigned the circuit board with repairability in mind, reducing its 90 soldering points to 10.

In line with this thought process, the headband is more flexible now. It is made of TPU, not leather, so it can self-repair from minor abrasions and stay strong yet bendy. The cable connecting both cups isn't inside the band. Instead, it is threaded through the silicone flap underneath to make it easily repairable.

Thoughtfully remade from scratch

Much of the internals of the Marshall Monitor III headphones were remade from scratch, including the audio drivers and acoustics, to achieve the desired performance boost. The makers of the headphones benchmarked them against less commercial-sounding studio monitors.

Tuned with Marshall's signature sound, these headphones deliver the full spectrum of sound with every instrument standing out clearly and getting its moment in the sun.

The Marshall app for Android and iOS simplifies the process of customizing your Monitor III. This is the main control hub for your headphones where you can adjust the equalizer, choose presets, or customize your own.

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Users can also customize the M-button, which is the shortcut button that opens Spotify as a default setting. The battery settings can be changed to prioritize battery health. There are several other options available in the app.

Once Auracast launches widely with Android 16, the app will help you to leverage the feature.

Speaking of the battery life... it rocks!

When all is said and done, the battery alone justifies the latest iteration of the Marshall Monitor ANC headphones. The brand straight up doubled the battery life, going from 30 hours with ANC on to 70 — that's right, 70 — hours of playback with ANC enabled. And once you turn the ANC off, Marshall promises up to 100 hours of playback. It's the wildest uptime I have ever witnessed from a pair of Bluetooth headphones of this stature.

I have put this to the test again and again, getting so bold as to charge it once on an international trip. These headphones did not disappoint. No lie was told here. At this point, I often forget when I last charged the Monitor III.

I enjoyed constant playback on two back-to-back flights, blocking out the agitating sound of in-air turbulence or the plane's roaring engines taking off. It was a sensory delight with no fear of the battery running out at the back of my mind. What a blissful travel accessory!

As if Marshall didn't spoil us enough with that ridiculous uptime, these headphones support fast charging. A quick 15-minute charge gives you 12 hours of playback. That's an infallible combo.

Should you buy the Marshall Monitor III ANC headphones?

Personally, I can find no deal-breaking flaw in the Marshall Monitor III headphones. I'd give them a five out of five, but the lack of hi-res audio support must be taken into consideration.

Another small issue that some folks might have with these headphones is the lack of a headphone jack. Many popular brands like Edifier include a headphone jack to USB-C converter as well as a standard 3.5mm audio cable with their Bluetooth headphones, since they usually support both forms of wired audio playback.

Marshall chose to forego the standard audio port, though you can still use the Type-C port for wired audio playback. There's also a USB-C to 3.5mm cable in the case, which can be used to connect the headphones to a computer or laptop that has an audio jack.

However, there's no way these minor drawbacks should hold you back from buying such a great, well-designed product. Something that's designed to last and is easily repairable deserves praise. This pair of headphones is Auracast-ready and has an insane battery life to boot, so I say go ahead and purchase it. You certainly won't regret it!