With its suave looks, class-leading battery life and phenomenal sound, the Marshall Stockwell III has become my go-to Bluetooth speaker

Marshall has been on a roll in 2026, adding to its lineups of headphones, home speakers, and now, portable Bluetooth speakers. For the past couple of weeks, I’ve been testing the Marshall Stockwell III which succeeds the seven-year-old Stockwell II — and it has quickly become my go-to speaker for almost everything.

The Stockwell III improves on its predecessor by doubling the battery life (over 40 hours now), being more waterproof thanks to its IP55 rating, and delivering punchier bass, brighter treble, and incredible 360° sound. Though a little expensive and slightly heavy for a portable speaker, those feel like minor issues in an otherwise compelling (and beautiful) package.

So, is this the best portable Bluetooth speaker for you? Read my full Marshall Stockwell III review to find out.

Marshall Stockwell III review: Specs

Marshall Stockwell III review: Price & availability

The Marshall Stockwell III was first announced on 9 June, 2026, over seven years after its predecessor, the Marshall Stockwell II. Available to buy from 18 August, the Stockwell III has a retail price of $249 / £199 — same as the second-gen model at launch in 2019. The Stockwell III comes in Black or Cream, and both have brass accents.

This is a premium portable Bluetooth speaker, and it finds itself competing with the likes of the Ultimate Ears Everboom ($249) and the Sonos Play ($299). Though a little expensive, it’s still cheaper than the Bang & Olufsen Beosound A1 3rd Gen which costs a whopping $399. The Stockwell III is worth the investment if you want 40+ hours of battery and beautiful sound stuffed into a compact (and stunning) package.

Marshall Stockwell III review: Design

The Marshall Stockwell III is, in a nutshell, a ridiculously sexy speaker, and the portable speaker to get if you care about aesthetics above all else. Not much has changed between the Stockwell III and its predecessor when it comes to portability. The third-gen model measures 7.1 x 6.4 x 2.9 inches and weighs 2.9lbs. To make it easier to carry around, Marshall has included a guitar-esque, velvet carry strap in the box, which can be attached to the Stockwell III’s sides.

Given its hefty weight, the Stockwell III isn’t the most portable speaker around. The Ultimate Ears Everboom is lighter at 2.1lbs, as is the Bang & Olufsen Beosound A1 3rd Gen which weighs 1.27lbs. The Stockwell III’s strap makes it slightly easier to carry around, but if you want an even lighter speaker but with Marshall’s looks, the Emberton III ($149, 1.5lbs) is a standout choice.

The Stockwell III looks more premium compared to its predecessor, too. While the Stockwell II featured white accents, the Stockwell III now features brass branding (on either black or cream), keeping in line with the brand’s other current-gen speakers — and headphones, too, like the Milton ANC ($229) and the Monitor III ($349). I much prefer this look as the black/cream and gold combo makes the speaker stand out in a crowded market.

Build quality is solid, thanks to metal mesh grilles and the textured silicone outer sleeve. You’re getting bang for your buck with the Stockwell III.

But why should you buy the Stockwell III instead of Marshall’s other more portable (ergo, lightweight) speakers? The Stockwell III is a mid-sized, premium Bluetooth speaker that’s clearly designed for both home (given the Placement Compensation feature within the app) and light outdoor use (given its IP55 rating).

It’s got a more luxurious feel to it than the ultra-portable Emberton III, for instance, but it’s smaller than a massive party speaker, like the Bromley 450 ($799). If you want a small speaker to travel with, and one that can withstand the elements, get the IP67-rated Emberton III. But if you want a mid-sized speaker that isn’t as expensive or bulky as the Kilburn III ($379), get the Stockwell III.

Weatherproofing

Marshall has made significant improvements to the Stockwell III’s durability as the third-gen model is now IP55-rated — the Stockwell II was only IPX4-rated. IP55 means the Stockwell III is protected from dust and is fairly water resistant, though you can’t submerge it underwater like you can the IP67-rated Ultimate Ears Everboom.

IP55 should suffice for most scenarios, but be mindful of using it in wet conditions repeatedly as any gadget’s waterproofing wears down over time.

Controls

All the buttons and dials are located on the Stockwell III’s top plate, and you’ll be familiar with them if you’ve used any of Marshall’s other speakers, like the Acton IV ($299). Even if you aren’t, getting to grips with the controls is quick and easy. All the buttons and dials give great tactile feedback when pressed or turned.

There’s a Source button for swapping between Bluetooth and AUX, and a customizable ‘M’ button that, by default, activates Spotify Tap so you can start playing music without opening the app on your phone; playback joystick; and three amp-like knobs for adjusting volume, treble and bass. Alongside these, Marshall has also added a handy battery indicator.

Connectivity

The Stockwell III features a 3.5mm jack and a USB-C port for wired playback, as well as Bluetooth 5.3 for wireless connectivity. Over Bluetooth, you get support for SBC, AAC and LC3 codecs — the latter delivers high efficiency and better sound quality at low bitrates. This also gives it a leg-up over the Ultimate Ears Everboom which supports SBC and AAC only.

While the Stockwell II featured traditional multi-speaker pairing with other Stockwell IIs, the Stockwell III is Auracast-enabled — and that’s better as it enables multiple devices to connect to a single audio source without pairing. The third-gen model utilizes Bluetooth LE to essentially connect to an unlimited number of other Auracast-enabled Marshall speakers, such as the Emberton III or other Stockwell IIIs.

You also get multipoint connectivity, which means that you can connect two different Bluetooth devices to the Stockwell III simultaneously. I did this with my MacBook Air M2 and Google Pixel 10 Pro XL and it worked seamlessly.

Marshall Stockwell III review: Sound quality

The Marshall Stockwell III is very loud for its size — it’s one of the best-sounding portable Bluetooth speakers around. Under the hood, the Stockwell III is fitted with a 65W Class D amplifier to power its 3-inch woofer, and two 31W Class D amplifiers for its dual 1.75-inch wide-band drivers (versus two 5W tweeters and a single 10W woofer on the Stockwell II). The speaker covers a frequency response range of 54Hz to 20KHz.

Marshall has clearly spared no expense when it comes to stuffing the Stockwell III to the brim — and the result is simply outstanding sound. To test the speaker, I listened to a range of songs on Qobuz, the best music streaming service for audiophiles. ‘2515’ by Wasia Project, which has a strong, pulsating bassline acting as the track’s backbone throughout, sounded sublime. The song’s dark electronic pulse came through with real weight, while the bass remained tight and controlled, and never became muddy — even at high volumes.

This is where Marshall’s ‘Dynamic Loudness’ comes into play. The Stockwell III borrows this from the Stanmore IV ($399) and the Acton IV, and it basically ensures that sound remains balanced and distortion-free regardless of the volume. Playing ‘2515’ at 80% volume didn’t overwhelm the speaker, as the lows maintained their warmth and richness.

I then listened to ‘Mariners Apartment Complex’ by Lana Del Rey to test the soundstage — and sure enough, the Stockwell III didn’t falter. Lana’s vocals sat front and center, with her words remaining clear and never bleeding into one another. There was a great balance between her remarkable vocals and the acoustic guitar and piano, and the strings sounded textured and defined. Also, the True Stereophonic 360° — found on the Bromley 750 ($1,299) and Bromley 450 party speakers — filled the room and the song sounded consistent when I moved around, giving the track an effortless sense of space and depth.

Lastly, I played ‘Papua New Guinea’ by The Future Sound of London, an electronic, ambient techno track. The driving basslines, swirling synths, breakbeat-style percussion and oscillating keyboard loops all came together to create a layered production, and the Stockwell III reproduced the dreamy nature extremely well. The treble felt vibrant and nuanced without becoming fatiguing. My partner and I couldn’t help but move along to the song, like we were at a rave.

Listen along to my review with the Marshall Stockwell III testing playlist:

Marshall Stockwell III review: App

The Marshall Stockwell III is accompanied by the Marshall Bluetooth app, available for free on iOS and Android. It’s the same app used by the British brand’s headphones and earbuds, and it’s your one-stop shop for adjusting the EQ or choosing a preset, updating the firmware, enabling Auracast, and customizing the ‘M’ button. The app sports a clean interface and is extremely easy to use.

You also get Placement Compensation, where you can select whether the speaker is close to an edge or corner, or flush against a wall. Once you’ve chosen your desired settings, the Stockwell III then corrects itself for any nearby reflective surfaces that may affect the sound quality. This feature has been borrowed from the Stanmore IV and Acton IV, which are plug-in home speakers. It’s handy to have if you’re keeping the Stanmore III in one place but given that it’s a portable Bluetooth speaker, I highly doubt you’ll be keeping it stationary.

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There’s a Source Mix option, too, which is new. It basically enables you to play music over Bluetooth and via USB-C at the same time. I can’t really think of a use case for this, but I suppose if you want to feel like a DJ, you can.

One thing I find surprising, though, is that the Stockwell III uses the Marshall Bluetooth app and not the new Marshall app (came out in 2026 before the Stockwell III) which its fourth-gen home speakers utilize. Wouldn’t it make sense to have all of its speakers in one app? I’m personally not a fan of having two separate apps for different devices. Maybe it’s because the Stockwell III was actually created before the Stanmore IV and Acton IV were. Perhaps this is something Marshall will fix later. This isn’t a complaint, anyway, just an observation.

Marshall Stockwell III review: Battery life

Marshall has fitted a bigger battery into the Stockwell III, and the speaker can now run for over 40 hours on a single charge. That’s double the Stockwell II’s battery life. The Stockwell III trumps its competition too, as the Sonos Play is rated for 24 hours, and the Ultimate Ears Everboom is rated for 20. Even the pricier Bang & Olufsen Beosound A1 3rd Gen is rated for just 24 hours.

In my testing, I played at 50% volume over multiple listening sessions. The total time it took for the Stockwell III to run out of battery was just over 40 hours, keeping in line with Marshall’s claims.

Similar to the Sonos Play, the Stockwell III doubles as a power bank and you can use a USB-C cable to charge your smartphone, laptop and other devices. This is a great feature to have in a portable speaker as you don’t need to worry about finding a socket to charge your phone if you’re, say, out on a hike.

Marshall Stockwell III review: Verdict

Just when I thought Marshall speakers couldn’t get any better, the iconic amp manufacturer comes out with something like the Stockwell III. This is an excellent portable speaker that delivers far more sound than its compact design suggests. Though it isn’t cheap — just shy of $250 — its combination of rich bass, vibrant treble and clear mids make a strong case for the price.

The Stockwell III also packs 40 hours of battery life, IP55 durability, and immersive 360° sound into a slim profile. While it’s still not the lightest portable speaker around, the included velvet strap makes it easier to carry around.

I can’t help but describe the speaker’s sound as genuinely astounding. If I had to take one speaker with me on my travels or to picnics outdoors, it would be the Stockwell III. At the time of writing, it’s Marshall’s best portable Bluetooth speaker right now.