Short answer: the Harman Kardon Onyx Studio 9. It ranks #15 of 113 boombox speakers by sound quality, rated 4.1/5, at $184.99. The Ruimatech RM-10 ranks #29, rated 3.8/5, at $159.99, $25 cheaper, which does not close the gap in sound quality.
Why pick the Harman Kardon Onyx Studio 9: An elegant living room portable with balanced, smooth, non-fatiguing sound, app EQ, and stereo pairing for music lovers. 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.
The Ruimatech RM-10 is the longer-running, tougher choice. An affordable three-way boombox with clear sound that holds up at full volume, water resistance and fast charging. It is rated for 14 hours of battery against 8 for the Harman Kardon Onyx Studio 9. It is rated IPX6, while the Harman Kardon Onyx Studio 9 has no water resistance. The tradeoff: 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 $25 you would save on the Ruimatech RM-10 does not close the gap.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Prices on this page were last checked November 14, 2026 at 6:17 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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Specifications Side By Side
| Harman Kardon Onyx Studio 9 | Ruimatech RM-10 | |
|---|---|---|
| Price | $184.99 | $159.99 |
| Ranked | #15 of 113 in Boombox Size Portable Bluetooth Speakers | #29 of 113 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) |
Where the Ratings Come From
- Harman Kardon Onyx Studio 9: reviews by Alan Ross.
- Ruimatech RM-10: reviews by Jagist and Josh’s Gadgets and More.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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