These are not really the same size class, and that is the honest framing here. The JBL Boombox 3 ranks #24 of 76 boombox speakers by sound quality at $399; the Marshall Stockwell III ranks #59 of 82 large speakers by sound quality at $249.99.
The case for the JBL Boombox 3: IP67 rated. The catch: Dips in mid bass range which makes the bass sound undefined, bass boosted, peaky at 700Hz, not quite as good mids and treble as the Blast.
What the Marshall Stockwell III does well: 40+ hour battery life with a user-replaceable battery, strap, sleeve and grilles. The catch: Highs are recessed by default and need the treble control maxed to compensate, still lacking detail even then.
Buy the JBL Boombox 3 ($399) for a boombox speaker; the Marshall Stockwell III ($249.99) suits a large speaker instead.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| JBL Boombox 3 | Marshall Stockwell III | |
|---|---|---|
| Price | $399.00 | $249.99 |
| Ranked | #24 of 76 in Boombox Size Portable Bluetooth Speakers | #59 of 82 in Large Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Aux Latency | 25ms | - |
| Bass Extension (-10dB) | 43Hz | - |
| Battery Life | 24 hours (Manufacturer specified) | 40+ hours (Manufacturer specified) |
| IP Rating | IP67 | IP55 |
| Bluetooth Latency | 100ms | - |
| Maximum SPL | 110dB (measured by Alan Ross Reviews) | - |
| Party Mode | Yes (PartyBoost up to 100 speakers) | - |
| Power Input | AC Power cable | USB-C |
| Stereo | Yes | Partially |
| Omnidirectional | No | Yes |
| TWS | Yes | No |
| Weight | 14.8 lbs (6.7 kg) | 2.9 lbs (1.3 kg) |
| Bluetooth Codecs | SBC | SBC, AAC, LE Audio with LC3 |
| App | No | Yes |
| EQ | No | Yes (parametric, via app) |
| Power Bank | Yes (USB-A) | Yes |
| USB Playback | No | - |
| Built-in Microphone | No | - |
| FM Tuner | No | - |
| Microphone Input | No | - |
| MicroSD Playback | No | - |
| Amplifier Power | 180W AC / 136W battery | 44W |
| Dimensions | 19” x 10.1” x 7.9” (482 x 257 x 200 mm) | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) |
| Drivers | 1x 189mm subwoofer + 2x 81mm woofers + 2x 20mm tweeters | 1x 3” woofer, 2x 1.75” wide-band drivers |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.3 | 5.3 |
| Strap | No | Yes (detachable strap) |
| Frequency Response | - | 54Hz - 20kHz (Manufacturer specified) |
Related Speaker Comparisons
More worthwhile head-to-heads for JBL Boombox 3:
- Earfun Uboom X vs JBL Boombox 3
- JBL Boombox 3 vs Tribit Stormbox Blast
- Harman Kardon Go + Play 3 vs JBL Boombox 3
- JBL Partybox Encore 2 vs JBL Boombox 3
- JBL Partybox Encore Essential 2 vs JBL Boombox 3
Prices on this page were last checked September 26, 2026 at 11:14 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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Speakers In Full
JBL Boombox 3: $399.00 Amazon eBay
Newer model: the JBL Boombox 4, rated 4/5.
Pros: IP67 rated. 24 hour battery life (6.5 hour charge time). Doubles as a power bank. PartyBoost links up to 100 compatible JBL speakers. Three-way speaker system with subwoofer. Measured bass extension of 43Hz (-10dB).
Cons: Dips in mid bass range which makes the bass sound undefined, bass boosted, peaky at 700Hz, not quite as good mids and treble as the Blast.
Full JBL Boombox 3 review and specifications →
| Amplifier Power | 180W AC / 136W battery |
|---|---|
| App | No |
| Aux Input | Yes |
| Aux Latency | 25ms |
| Bass Extension (-10dB) | 43Hz |
| Battery Life | 24 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 100ms |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 19” x 10.1” x 7.9” (482 x 257 x 200 mm) |
| Drivers | 1x 189mm subwoofer + 2x 81mm woofers + 2x 20mm tweeters |
| EQ | No |
| FM Tuner | No |
| IP Rating | IP67 |
| Maximum SPL | 110dB (measured by Alan Ross Reviews) |
| MicroSD Playback | No |
| Microphone Input | No |
| Omnidirectional | No |
| Party Mode | Yes (PartyBoost up to 100 speakers) |
| Power Bank | Yes (USB-A) |
| Power Input | AC Power cable |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| USB Playback | No |
| Weight | 14.8 lbs (6.7 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Oluv Patreon: Earfun UBoom X vs JBL Boombox 3 - outdoor test More from Oluv’Sone →
- Alan Ross Reviews: JBL Boombox 3 review vs JBL Boombox 2 a subwoofer and a 3 way equals heaven? 💋 More from alanrossreviews →
- Alan Ross Reviews: W King T11 party boombox and Karaoke machine review vs T9, Stormbox Blast and Boombox 3.
- Dominik Reviews: JBL Boombox 3 vs 2x Tribit Stormbox Blast 🤑 Huge difference? More from Dominik Reviews →
- Alan Ross Reviews: Not quite! JBL Authentics 300 review and sound test vs Boombox 3, Encore and Stormbox Blast
- Alan Ross Reviews: WiFi Edition: JBL Boombox 3 ultimate review! vs Boombox 3 Bluetooth edition
- Oluv Patreon: Earfun UBoom X vs JBL Boombox 3 - outdoor
- Jay’s Straight Up Reviews & More: Zealot ZE21 vs JBL Boombox 3 Tailgater Special @20ft. The Budget Beast Against the OG Boombox More from JaysStraightUpReviews →
- Jay’s Straight Up Reviews & More: Tribit Stormbox Blast 2 vs JBL Boombox 3 🔊 Got Bass? Let’s See How They Compare 😲 Battery Powered 🔋
- Picky Audio: SO CLOSE! Soundcore Boom 2 Plus vs JBL Boombox 3 More from pickyaudio →
- Picky Audio: Extended Sound Test (Soundcore Boom 2 Plus vs JBL Boombox 3)
- Alan Ross Reviews: W-King X20 JBL Boombox 3 killer! this should be illegal! - I was shocked!
- Jay’s Straight Up Reviews & More: New! W-King X20 vs JBL Boombox 3 🛜 Head to Head 🔋Battery Powered 📊Custom EQ - Links In Description
- Alan Ross Reviews: W-King X20 JBL Boombox 3 killer! this should be illegal! - I was shocked!
- Jay’s Straight Up Reviews & More: New! W-King X20 vs JBL Boombox 3 🛜 Head to Head 🔋Battery Powered 📊Custom EQ - Links In Description
- Alan Ross Reviews: Tronsmart Bang Max Review, JBL Boombox 3 wannabe 130w
- Jay’s Straight Up Reviews & More: Skullcandy BARREL XT vs JBL Boombox 3 🤯Budget Banger vs Reigning Champ 🔋 Battery Powered 🏠 Indoors
- Jay’s Straight Up Reviews & More: SONY ULT Field 7 💣vs JBL Boombox 3 🧨 Showdown! 🪇Let’s Shake it Up! 🔋Battery Powered Basement Battle
- AudioTribe: JBL Authentics 500 VS JBL Boombox 3 Sound Test Comparison
- Head-to-Head Comparisons
- JBL Boombox 3 vs Tribit Stormbox Blast 2
- JBL Boombox 3 vs JBL Boombox 3 Wifi
- JBL Boombox 3 vs LG Xboom Stage 301
- JBL Boombox 3 vs Harman Kardon Onyx Studio 5
- JBL Boombox 3 vs Harman Kardon Go + Play 2
- JBL Boombox 3 vs Zealot S95
- JBL Boombox 3 vs JBL Boombox 4
- JBL Boombox 3 vs Zealot ZE01
- See all 74 comparisons
Marshall Stockwell III: $249.99 Marshall eBay
Older model: the Marshall Stockwell II (rated 4.5/5).
Pros: 40+ hour battery life with a user-replaceable battery, strap, sleeve and grilles. Doubles as a USB-C power bank. IP55 dust/water resistance. App includes parametric EQ, a Soundstage widening control, and wall/corner placement compensation. Endless-rotation control knobs.
Cons: Highs are recessed by default and need the treble control maxed to compensate, still lacking detail even then. Bass tends to sound resonant and boomy, with reported frequency cancellation and phase issues on complex material that EQ doesn’t fully resolve. Oluv’s A/B testing against the outgoing Stockwell II finds the default tuning muffled and muddy enough to prefer the seven-year-old original out of the box, and output loses dynamics and bass while turning harsh well below maximum volume. No aptX support.
Full Marshall Stockwell III review and specifications →
| Amplifier Power | 44W |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Battery Life | 40+ hours (Manufacturer specified) |
| Bluetooth Codecs | SBC, AAC, LE Audio with LC3 |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) |
| Drivers | 1x 3” woofer, 2x 1.75” wide-band drivers |
| EQ | Yes (parametric, via app) |
| Frequency Response | 54Hz - 20kHz (Manufacturer specified) |
| IP Rating | IP55 |
| Omnidirectional | Yes |
| Power Bank | Yes |
| Power Input | USB-C |
| Stereo | Partially |
| Strap | Yes (detachable strap) |
| TWS | No |
| Weight | 2.9 lbs (1.3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Marshall Stockwell III vs Turtlebox Cub
- Marshall Stockwell III vs Xdobo X8 Max
- Marshall Stockwell III vs Klipsch Detroit
- Marshall Stockwell III vs Ultimate Ears Epicboom
- Marshall Stockwell III vs Doss Soundbox XL
- Marshall Stockwell III vs Dali Katch G2
- Marshall Stockwell III vs Tronsmart Halo 100
- Marshall Stockwell III vs B&O Beosound Level
- See all 60 comparisons