Marshall, a well-known brand for its guitar amplifiers and stage equipment used by legendary musicians like Jimi Hendrix and Angus Young, has expanded its product line over the past decade to include headphones, earbuds, and Bluetooth speakers. The latest addition to this range is the Stockwell III, a compact speaker positioned between the Emberton and Middleton models in terms of size and features. Unlike its horizontal counterparts, the Stockwell III has a vertical design, offering a more elegant and stylized look while retaining key attributes like durability, long battery life, and weather resistance. The Stockwell III measures 15 cm in width, 7.2 cm in depth, and 18.1 cm in height, weighing 1300 grams. It features an IP55 rating, which means it can withstand dust and water splashes. The speaker includes a synthetic leather strap, inspired by guitar straps, lined with red felt inside, allowing it to be carried like a small bag. Sound is emitted from both the front and back of the speaker, a feature Marshall calls "True Stereophonic 360," which spreads audio in a 180-degree arc. The startup and shutdown sounds are now synchronized with the user's selected volume level for a more personalized experience. In terms of connectivity, the Stockwell III offers a 3.5 mm auxiliary input, a USB-C port for charging and playing music, and support for Bluetooth codecs like SBC, AAC, and LC3. It also supports Auracast technology, enabling users to connect to ongoing audio broadcasts, such as live events or radio stations. Internally, the speaker includes an active 8 cm bass driver, a passive radiator on the back, and two 4 cm high-frequency drivers. It delivers 65 watts of power for the bass and 31 watts for each high-frequency speaker, providing a robust audio experience. The Marshall app allows users to customize the sound further with a parametric equalizer, placement optimization, and a soundstage expander. The speaker is described as delivering a warm and balanced sound, with a detailed midrange and slightly bright treble. While it performs well across various music genres, the bass loses some depth at very high volumes. The soundstage is narrow but can be slightly widened using the app. The Stockwell III offers more than 40 hours of battery life, doubling the autonomy of the previous model. It can be charged via USB-C Power Delivery and supports up to 30 watts of charging power. The battery, as well as the front and back grilles, silicone cover, and strap, are all replaceable. This modularity aligns with upcoming European regulations on battery design, making the speaker more sustainable and user-friendly. Priced at 229 euros, the Marshall Stockwell III became available on August 18, 2026. It competes with other portable speakers like the JBL Charge 6 and Sony ULT Field 5, each offering different features and price points to cater to a variety of consumer needs.