Short answer: the Brane X for deep bass, the Stockwell III for carrying around. The Brane X pairs a dedicated subwoofer with a measured 31Hz -10dB bass extension and adds Wi-Fi, AirPlay and premium codecs for $549, with a 12-hour battery that suits a stationary setup. The Stockwell III weighs 2.9 lbs (1.3 kg), runs 40+ hours and costs $249.99, so it is the one that leaves the house.
This pits Marshall’s mid-priced portable against a high-end system built around real bass extension. The Stockwell III offers a compact 2.9 lbs (1.3 kg) cabinet, parametric EQ, and a 40+ hour battery for $249.99. The Brane X pairs a dedicated subwoofer with midrange drivers and tweeters for a measured 31Hz -10dB bass extension, plus Wi-Fi, AirPlay, and premium Bluetooth codecs, in a 7.7 lbs (3.5 kg) cabinet for $549.
Choose the Brane X for bass extension and versatility: Independent testing finds it loud with well-balanced mids and useful bass-level controls, reaching far deeper than the Stockwell III, and its Wi-Fi/AirPlay support and 12-hour battery suit a stationary high-end setup.
Choose the Stockwell III for a lighter, far cheaper speaker: At under half the Brane X’s weight and price, it’s the more practical choice for actually carrying around rather than leaving in one spot.
Buy the Brane X. It is rated higher for sound quality, and the $299.01 saving on the Marshall Stockwell III is not enough to make up the difference.
Looking for alternatives? See the complete Portable Bluetooth rankings.
A stylish, rugged speaker with a very long battery you can swap yourself, a detailed app EQ, and power bank charging.
A portable speaker with extraordinarily deep bass for its size, plus Wi-Fi, AirPlay, Alexa and a low latency aux input.
Prices on this page were last checked October 31, 2026 at 7:11 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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Specifications Side By Side
| Marshall Stockwell III | Brane X | |
|---|---|---|
| Price | $249.99 | $549.00 |
| Ranked | #79 of 115 in Large Size Portable Bluetooth Speakers | #4 of 115 in Large Size Portable Bluetooth Speakers |
| Drivers | 1x 3” woofer, 2x 1.75” wide-band drivers | 2x 2.5” midrange, 2x 0.75” tweeters + 6.5”x9” subwoofer |
| Frequency Response | 54Hz - 20kHz (Manufacturer specified) | 30Hz - 20kHz (Manufacturer specified) |
| Amplifier Power | 44W | 200W |
| Battery Life | 40+ hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | 5.1 |
| Bluetooth Codecs | SBC, AAC, LE Audio with LC3 | aptX HD, aptX, AAC, SBC |
| IP Rating | IP55 | IP57 |
| Weight | 2.9 lbs (1.3 kg) | 7.7 lbs (3.5 kg) |
| Dimensions | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) | 9.3” x 7” x 6.1” (236 x 178 x 155 mm) |
| App | Yes | Yes (Brane app) |
| EQ | Yes (parametric, via app) | Yes (5 band) |
| Aux Input | Yes | Yes |
| Digital Aux Input | No | No |
| Power Bank | Yes | No |
| Power Input | USB-C | AC Power brick |
| Stereo | Partially | Yes |
| Omnidirectional | Yes | No |
| TWS | No | Yes |
| Strap | Yes (detachable strap) | No |
| Aux Latency | - | 295ms default, 33ms with aux pass-through |
| Bass Extension (-10dB) | - | 31Hz |
| Bluetooth Latency | - | 100ms |
| Maximum SPL | - | 106dB (measured by Alan Ross Reviews) |
| Party Mode | - | Yes (Brane app, up to 8 speakers) |
| Wi-Fi | - | Yes |
| Built-in Microphone | - | Yes |
| Voice Assistants | - | Amazon Alexa |
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