Short answer: the Marshall Stockwell III, if you are buying new. The Harman Kardon Onyx Studio 4 ranks higher than it (#65 vs #76 of 102 large speakers, 3.3/5 vs 3.0/5) but is discontinued, so only consider it used; the Marshall Stockwell III is still sold new at $249.99.
The case for the Harman Kardon Onyx Studio 4: Balanced sound quality with deep resonant bass and crisp treble, large dynamic range. The catch: 8 hour battery at medium volume.
The Marshall Stockwell III is the longer-running, lighter pick. 40+ hour battery life with a user-replaceable battery, strap, sleeve and grilles. It is rated for 40 hours of battery against 8 for the Harman Kardon Onyx Studio 4. At 2.9 lbs (1.3 kg) it weighs noticeably less than the Harman Kardon Onyx Studio 4 at 4.5 lbs (2.06 kg). It is rated IP55, while the Harman Kardon Onyx Studio 4 has no water resistance. The catch: Highs are recessed by default and need the treble control maxed to compensate, still lacking detail even then.
Buy the Marshall Stockwell III, since the Harman Kardon Onyx Studio 4 is discontinued and only worth hunting down used.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 4 | Marshall Stockwell III | |
|---|---|---|
| Price | $100 Discontinued | $249.99 |
| Ranked | #65 of 102 in Large Size Portable Bluetooth Speakers | #76 of 102 in Large Size Portable Bluetooth Speakers |
| App | Yes (HK Connect) | Yes |
| Aux Input | Yes | Yes |
| Battery Life | 8 hours (Manufacturer specified) | 40+ hours (Manufacturer specified) |
| EQ | No | Yes (parametric, via app) |
| IP Rating | None | IP55 |
| Party Mode | Yes (Connect+ up to 100 speakers) | - |
| Power Bank | No | Yes |
| TWS | Yes | No |
| Weight | 4.5 lbs (2.06 kg) | 2.9 lbs (1.3 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC, AAC, LE Audio with LC3 |
| Built-in Microphone | Yes | - |
| Power Input | DC Barrel Connector (19V/2.1A) | USB-C |
| Stereo | Yes | Partially |
| Omnidirectional | No | Yes |
| Bluetooth Version | 4.2 | 5.3 |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters + 1x passive radiator | 1x 3” woofer, 2x 1.75” wide-band drivers |
| Dimensions | 11.4” x 11.4” x 5.1” (290 x 290 x 130 mm) | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) | 54Hz - 20kHz (Manufacturer specified) |
| Amplifier Power | 60W | 44W |
| Digital Aux Input | No | No |
| Strap | No | Yes (detachable strap) |
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Prices on this page were last checked October 4, 2026 at 9:58 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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The Two Speakers In Full
Harman Kardon Onyx Studio 4: $100 Discontinued eBay
Newer model: the Harman Kardon Onyx Studio 9, rated 4.1/5.
Pros: Balanced sound quality with deep resonant bass and crisp treble, large dynamic range. Multi-host Bluetooth connectivity for 2 phones, daisy chaining up to 100 speakers. Elegant modern design with smooth curves and premium materials.
Cons: 8 hour battery at medium volume. Not at loud as others. Not as deep of bass as the newer Onyx. External AC power brick for charging. Discontinued.
Full Harman Kardon Onyx Studio 4 review and specifications →
| Amplifier Power | 60W |
|---|---|
| App | Yes (HK Connect) |
| Aux Input | Yes |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.4” x 11.4” x 5.1” (290 x 290 x 130 mm) |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters + 1x passive radiator |
| EQ | No |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) |
| IP Rating | None |
| Omnidirectional | No |
| Party Mode | Yes (Connect+ up to 100 speakers) |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2.1A) |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| Weight | 4.5 lbs (2.06 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 4 vs Tronsmart Halo 100
- Harman Kardon Onyx Studio 4 vs Zealot S97
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- Harman Kardon Onyx Studio 4 vs JBL Xtreme 2
- Harman Kardon Onyx Studio 4 vs Doss Soundbox XL
- Harman Kardon Onyx Studio 4 vs W-King D8
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- Harman Kardon Onyx Studio 4 vs Klipsch Detroit
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Marshall Stockwell III: $249.99 Marshall eBay
Older model: the Marshall Stockwell II (ranked higher, 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 | Yes |
| 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
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