The Stanmore 3 is a stationary speaker powered by AC only, with a 2.1 setup that includes a 50W Class D amp for the woofer and two 15W amps for the tweeters. It delivers a balanced sound signature with physical controls for bass and treble, and supports Bluetooth 5.2 (with LE Audio readiness).
The JBL Boombox 3, by contrast, is built for heavy-duty portability—it packs a three-way speaker system with a dedicated subwoofer and offers up to 136W on AC and 60W on battery. It uses Bluetooth 5.3, has an IP67 waterproof and dustproof rating, and delivers up to 24 hours of battery life. It’s heavier at around 6.7 kg, but it comes with a sturdy handle for transport. If I were choosing based strictly on specs, I’d say the Boombox 3 is designed to go loud and long no matter the location, while the Stanmore 3 is all about precision and presence in a fixed, indoor space (and has a nice retro vintage aesthetic for home interior décor).
Specs Comparison
The Stanmore 3 is designed as a home speaker and not for portability. It plugs into AC power and doesn’t come with a battery, so it’s meant to stay put. It uses a three-amplifier setup—50 watts for the woofer and 15 watts for each tweeter—which gives it a total output of 80 watts. It runs on Bluetooth 5.2 and is ready for LE Audio, though that’s still not widely supported. I like that it gives you analog control knobs for volume, bass and treble. That kind of physical interface feels intuitive and lets me shape the sound without needing to open an app. The frequency range covers from 45 Hz up to 20 kHz, and while it doesn’t dig super deep into sub-bass territory, it has a clean and well-balanced sound for most music styles.
The Boombox 3 is a whole other beast and is primarily designed for rugged outdoors. It’s got a battery that pushes playback up to 24 hours and supports both AC and battery operation. On AC power, it hits 136 watts total—60 watts from the woofer, 30 watts from each midrange driver, and 15 watts from each tweeter. When running on battery, the total drops to 60 watts, but it still packs a punch. It uses Bluetooth 5.3 and supports multi-speaker pairing via JBL’s Auracast. The IP67 rating means it’s fully waterproof and dustproof, and it weighs over 6.7 kilograms, so while it’s portable, it’s not something I’d throw in a backpack—it’s more of a carry-it-by-the-handle kind of device. It also has a wider frequency response, going from 40 Hz to 20 kHz, which gives it a little more depth in the low end compared to the Stanmore.
For me, the Stanmore 3 is a better fit for calm, curated listening in a controlled indoor space. It looks good on a shelf and sounds tight and intentional. The Boombox 3 feels more like a party machine. It’s overbuilt, loud and meant to be taken anywhere without worrying about damage or power outlets. From a pure spec perspective, the Boombox 3 is more versatile and more powerful, but the Stanmore 3 is more elegant and focused in what it offers.
Table Comparison
| Specification | Marshall Stanmore III | JBL Boombox 3 |
| Power Output | 80W total: 50W Class D amplifier for the woofer and two 15W Class D amplifiers for the tweeters | AC mode: 1x 80W subwoofer + 2x 40W midrange + 2x 10W tweeters (180W total). Battery mode: 136W total |
| Frequency Response | 45 Hz – 20,000 Hz | 40 Hz – 20,000 Hz |
| Bluetooth Version | Bluetooth 5.2 (LE Audio ready) | Bluetooth 5.3 with Auracast |
| Battery Life | Not applicable (requires AC power) | Up to 24 hours of playtime |
| Charging Time | Not applicable | Approximately 6.5 hours |
| Water/Dust Resistance | None | IP67 rated (dustproof and waterproof) |
| Connectivity Options | Bluetooth, 3.5 mm input, RCA input | Bluetooth, 3.5 mm audio input, USB-C powerbank functionality |
| Dimensions (W x H x D) | 350 x 203 x 188 mm (13.78 x 8.00 x 7.40 in) | 482 x 257 x 200 mm (19.0 x 10.1 x 7.9 in) |
| Weight | 4.25 kg (9.37 lbs) | 6.7 kg (14.7 lbs) |
| Additional Features | Analog knobs for volume, bass, treble; Placement Compensation; Dynamic Loudness; Marshall Bluetooth app support | JBL PartyBoost; built-in powerbank; EQ presets via JBL Portable app; rugged handle; waterproof and dustproof housing |
Sound Comparison
The first thing I noticed when switching between the Marshall Stanmore 3 and the JBL Boombox 3 was how differently they approached bass. I played “After Dark” by Mr. Kitty on both speakers, and on the Stanmore 3, the bass felt tighter and more refined. It didn’t go as deep as the Boombox, but the 50W woofer gave a clean and controlled low end that sat nicely under the synths. With two 15W tweeters handling the highs, there was a sense of balance and stereo width that made it feel open even in a small room. I liked how the analog knobs let me make subtle EQ adjustments right from the speaker—it gave me more control over the sound without needing to mess with an app.
The JBL Boombox 3 brought a different kind of energy with deeper bass. Playing “Feel the Volume” by Jauz at higher levels, the power from its 80W subwoofer (when plugged in) was obvious. It dug deeper into the low frequencies and had a physical impact in the room. The midrange drivers helped it keep clarity even when pushed loud, but compared to the Stanmore, the treble felt a little less smooth—especially noticeable in tracks with delicate vocals like “Liability” by Lorde. On battery power, I could still feel the power drop slightly, but the sound stayed full and heavy. It’s the kind of speaker that makes you want to turn it up and move around, especially in a big open space or outdoors.
Testing both with “Nude” by Radiohead gave me a good sense of how they handle layered and atmospheric music. The Stanmore 3 pulled apart the vocals, strings, and reverb effects in a way that felt more deliberate and airy. I could hear the texture in Thom Yorke’s voice more clearly, and the quieter moments came through with more nuance. The Boombox 3 kept the energy alive but blurred some of the finer details in favor of warmth and punch. Personally, I think the Stanmore 3 is better for listening at home when I want to actually sit down and enjoy an album. The Boombox 3 is more fun when I’m with people and need volume and weight—it’s less about the finesse and more about the presence.
Design Comparison
The Marshall Stanmore 3 has vintage aesthetic and is wrapped in textured vinyl with a solid wood frame underneath, and the top panel is dressed with brass-like knobs for volume, bass and treble—there’s something satisfying about physically turning a knob instead of swiping through an app. It feels weighty at around 4.25 kg but in a good way—it’s not meant to be portable. I placed it on a shelf in my living room and it blended in like a piece of furniture, not a gadget. Even though there’s no battery or weather sealing, it feels like a timeless piece of gear that was built to live in one place and do one job really well. Overall, it’s very classy and blends in nicely with modern contemporary interior décor.
The Boombox 3 is designed as a rugged outdoor speaker. It’s bulky and bold, made to be seen and used outdoors. It weighs over 6.7 kg, but JBL gave it a strong metal handle with a thick silicone grip that makes carrying it feel manageable. The speaker is wrapped in a rugged fabric mesh and the exposed passive radiators at each end feel like a reminder that this thing is all about impact. It’s rated IP67, which means I didn’t worry about splashes or dust when I took it outside. The layout is simple—rubberized buttons across the top and protected ports under a sealing flap on the back. When I placed it next to the Stanmore 3, it felt more like a tool than a piece of decor, but that makes sense for what it’s designed to do.
Personally, I think the Stanmore 3 wins when it comes to indoor aesthetics and tactile design. It invites you to sit down, dial in your sound, and enjoy the experience. The Boombox 3 is all about durability and volume on the move. It feels tougher and more practical when you’re going outside or hosting something that might get messy.
The Verdict?
Personally, I would go with the Marshall Stanmore 3 if I were setting up a speaker that’s going to stay in my living room. The design feels aesthetic and vintage—from the vintage cabinet to the analog controls—and it delivers a smooth, balanced sound that holds up really well in casual listening and focused sessions. With 80 watts split across a 50W woofer and two 15W tweeters, it fills a room without trying too hard, and it sounds especially good with detailed or atmospheric tracks. I like having the freedom to tweak bass and treble physically, and for something I don’t need to move, the lack of portability isn’t really a downside. It’s a speaker that feels like part of the room—not just something I use, but something I want to keep around.
That said, I think the JBL Boombox 3 is the better choice for people who want power, durability and movement. It’s louder, heavier and built to go wherever the party is. The 180-watt output (on AC) pushes more air and hits harder, especially on bass-heavy tracks, and the IP67 rating means it’s not afraid of water, sand or dust. It’s not as refined in its tuning and can blur the details in quieter music, but that’s not really what it’s built for. If I were spending more time outside, or needed something that could handle rougher environments without skipping a beat, the JBL Boombox 3 is a great choice.