Short answer: the Harman Kardon Onyx Studio 9. It ranks #15 of 89 boombox speakers by sound quality, rated 4.1/5, at $189.99. The Ruimatech RM-10 ranks #28, rated 3.8/5, at $159.99, $30 cheaper, which does not close the gap in sound quality.
Why pick the Harman Kardon Onyx Studio 9: 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. Watch for: It has no water resistance, aux input or USB playback, and its eight-hour claimed battery life is short for an outdoor portable.
Why pick the Ruimatech RM-10: A three-way boombox (80W woofer, two 20W midranges, two 10W tweeters and dual passive radiators, 140W RMS) with a hi-fi leaning clarity, highs that don’t get screechy at max volume, and bass that holds on at full volume. The catch: It is tuned bass boosted, much like the JBL Boombox 3.
Buy the Harman Kardon Onyx Studio 9. It is rated higher for sound quality, and the $30 you would save on the Ruimatech RM-10 does not close the gap.
There is a real gap in water resistance: the Ruimatech RM-10 at IPX6 (powerful water jets) against the Harman Kardon Onyx Studio 9, which has no water resistance.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | Ruimatech RM-10 | |
|---|---|---|
| Price | $189.99 | $159.99 |
| Ranked | #15 of 89 in Boombox Size Portable Bluetooth Speakers | #28 of 89 in Boombox Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | 41Hz | - |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) | - |
| IP Rating | None | IPX6 |
| Power Input | AC Power Cable (2-Prong) | - |
| Stereo | Yes | Partially |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 9.3 lbs (4.2 kg) | - |
| App | Yes (Harman Kardon One app) | No |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | - |
| EQ | Yes (App EQ) | - |
| Party Mode | Yes (Auracast) | - |
| USB Playback | No | - |
| Bluetooth Version | 5.3 | 5.3 |
| Battery Life | 8 hours (Manufacturer specified) | 14 hours at 30% volume (Manufacturer specified) |
| Amplifier Power | 50W RMS | 140W RMS (300W peak) |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) | - |
| Drivers | 120mm woofer + 3x 20mm tweeters | 80W woofer + 2x 20W midranges + 2x 10W tweeters + 2 passive radiators |
| Digital Aux Input | No | - |
| Aux Input | No | - |
| Strap | No | No |
| Power Bank | - | Yes (USB-C) |
Related Speaker Comparisons
How Harman Kardon Onyx Studio 9 compares with other leading options:
- 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
- JBL PartyBox On-The-Go 2 Plus vs Harman Kardon Onyx Studio 9
Prices on this page were last checked September 30, 2026 at 2:57 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 (ranked higher, rated 4.1/5), the Harman Kardon Onyx Studio 7 (ranked higher, rated 4.1/5), the Harman Kardon Onyx Studio 6 (ranked higher, rated 4.1/5), the Harman Kardon Onyx Studio 5 (ranked lower, 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 | Yes |
| 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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Ruimatech RM-10: $159.99 Amazon eBay
Pros: A three-way boombox (80W woofer, two 20W midranges, two 10W tweeters and dual passive radiators, 140W RMS) with a hi-fi leaning clarity, highs that don’t get screechy at max volume, and bass that holds on at full volume. Side by side it beat the W-King X20S and X20 and sounded as good as the Tribit Stormbox Blast 2, especially at higher volume. IPX6, a claimed 14 hours, a USB-C power bank, 30W fast charging and stereo pairing.
Cons: It is tuned bass boosted, much like the JBL Boombox 3. There is no app or custom EQ and no shoulder strap, and the design is plain.
Full Ruimatech RM-10 review and specifications →
| Amplifier Power | 140W RMS (300W peak) |
|---|---|
| App | No |
| Battery Life | 14 hours at 30% volume (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Version | 5.3 |
| Drivers | 80W woofer + 2x 20W midranges + 2x 10W tweeters + 2 passive radiators |
| IP Rating | IPX6 |
| Omnidirectional | No |
| Power Bank | Yes (USB-C) |
| Stereo | Partially |
| Strap | No |
| TWS | Yes |
- Reviews, Comparisons and Sound Samples
- Jagist reviews: Ruimatech RM-10 Vs W-king X20!!! Battle Of Affordability!!! More from Jagistreviews →
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