Short answer: the Harman Kardon Onyx Studio 9. It ranks #15 of 76 boombox speakers by sound quality, rated 4.1/5, at $189.99; the onn Pro X Large Boom Boombox ranks #35, rated 3.4/5, and costs $199, so there is not much of a tradeoff to weigh.
What the Harman Kardon Onyx Studio 9 does well: An elegant 4.2kg living-room portable with a measured 41Hz -10dB bass point, 101dB maximum level, three tweeters, app EQ, stereo pairing and Auracast multi-speaker linking. The tradeoff: It has no water resistance, aux input or USB playback, and its eight-hour claimed battery life is short for an outdoor portable.
The case for the onn Pro X Large Boom Boombox: High rated power for the price at 180W RMS (540W peak). The catch: Bass not as deep as higher ranked speakers like the JBL Boombox 3, JBL Boombox 4, or Tribit Stormbox Blast.
Buy the Harman Kardon Onyx Studio 9. It is rated higher for sound quality than the onn Pro X Large Boom Boombox and costs less, so only choose the other one for a particular feature it does better.
There is a real gap in water resistance: the onn Pro X Large Boom Boombox at IP67 (brief submersion) against the Harman Kardon Onyx Studio 9, which has no water resistance.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | onn Pro X Large Boom Boombox | |
|---|---|---|
| Price | $189.99 | $199.00 |
| Ranked | #15 of 76 in Boombox Size Portable Bluetooth Speakers | #35 of 76 in Boombox Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | 41Hz | - |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) | - |
| IP Rating | None | IP67 |
| Power Input | AC Power Cable (2-Prong) | AC Power cord |
| Stereo | Yes | - |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 9.3 lbs (4.2 kg) | 17.2 lbs (7.8 kg) |
| App | Yes (Harman Kardon One app) | - |
| Bluetooth Codecs | SBC | SBC (inferred; additional codecs unverified) |
| EQ | Yes (App EQ) | Yes (Bass Boost) |
| Party Mode | Yes (Auracast) | Yes (Auracast) |
| USB Playback | No | - |
| Bluetooth Version | 5.3 | 5.4 (Manufacturer specified) |
| Battery Life | 8 hours (Manufacturer specified) | 20 hours (Manufacturer specified) |
| Amplifier Power | 50W RMS | 180W RMS (540W peak) |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) | 20.1” x 10.3” x 9” (510 x 261 x 228 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters | 5 speakers |
| Digital Aux Input | No | No |
| Aux Input | No | Yes |
| Strap | No | - |
| Removable Battery | - | No |
| Power Bank | - | Yes (USB-A, 5V/2A) |
| Discontinued | - | No |
| Frequency Response | - | 50Hz - 20kHz (Manufacturer specified) |
| Lights | - | Yes |
Related Speaker Comparisons
More worthwhile head-to-heads for Harman Kardon Onyx Studio 9:
- Earfun Uboom X vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 9 vs Tribit Stormbox Blast
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 9
- JBL Partybox Encore 2 vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 9 vs JBL Partybox Encore Essential 2
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.
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The Two Speakers In Full
Harman Kardon Onyx Studio 9: $189.99 Amazon eBay
Older models: the Harman Kardon Onyx Studio 8 (rated 4.1/5), the Harman Kardon Onyx Studio 7 (rated 4.1/5), the Harman Kardon Onyx Studio 6 (rated 4.1/5), the Harman Kardon Onyx Studio 5 (rated 3.9/5) and the Harman Kardon Onyx Studio 4 (rated 3.3/5).
Pros: An elegant 4.2kg living-room portable with a measured 41Hz -10dB bass point, 101dB maximum level, three tweeters, app EQ, stereo pairing and Auracast multi-speaker linking. Reviews praise its balanced, smooth presentation and non-fatiguing treble, making it a more music-focused choice than most party speakers. Measured bass extension of 41Hz (-10dB).
Cons: It has no water resistance, aux input or USB playback, and its eight-hour claimed battery life is short for an outdoor portable. Bass is less deep than some earlier Onyx Studio models, while the slightly recessed mids and rolled-off top end mean it is not the most open or detailed option; it still charges from an AC power cable rather than USB-C.
Full Harman Kardon Onyx Studio 9 review and specifications →
| Amplifier Power | 50W RMS |
|---|---|
| App | Yes (Harman Kardon One app) |
| Aux Input | No |
| Bass Extension (-10dB) | 41Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters |
| EQ | Yes (App EQ) |
| IP Rating | None |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Input | AC Power Cable (2-Prong) |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| USB Playback | No |
| Weight | 9.3 lbs (4.2 kg) |
- Links
- Reviews, Comparisons and Sound Samples
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onn Pro X Large Boom Boombox: $199.00 Walmart eBay
Pros: High rated power for the price at 180W RMS (540W peak). IP67 waterproof design for indoor and outdoor use. 20 hour battery life. 6 LED lighting modes. Party Mode supports multiple devices.
Cons: Bass not as deep as higher ranked speakers like the JBL Boombox 3, JBL Boombox 4, or Tribit Stormbox Blast. Frequency response isn’t as smooth as the top ranked speakers. Charges via AC cable rather than USB-C. Only available in the United States and Canada.
Full onn Pro X Large Boom Boombox review and specifications →
| Amplifier Power | 180W RMS (540W peak) |
|---|---|
| Aux Input | Yes |
| Battery Life | 20 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.4 (Manufacturer specified) |
| Digital Aux Input | No |
| Dimensions | 20.1” x 10.3” x 9” (510 x 261 x 228 mm) |
| Discontinued | No |
| Drivers | 5 speakers |
| EQ | Yes (Bass Boost) |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) |
| IP Rating | IP67 |
| Lights | Yes |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Bank | Yes (USB-A, 5V/2A) |
| Power Input | AC Power cord |
| Removable Battery | No |
| TWS | Yes |
| Weight | 17.2 lbs (7.8 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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