Short answer: the Harman Kardon Onyx Studio 9, if you are buying new. The EarFun Uboom X ranks higher than it (#1 vs #15 of 113 boombox speakers, 4.7/5 vs 4.1/5) but is discontinued, so only consider it used; the Harman Kardon Onyx Studio 9 is still sold new at $184.99.
The case for the Harman Kardon Onyx Studio 9: Auracast multi-speaker connection alongside classic stereo pairing. Set against that: Slight recessed mids, boost in the upper mids, rolled off upper treble.
Buy the Harman Kardon Onyx Studio 9 new; the EarFun Uboom X is no longer sold new, so it only makes sense as a used find.
There is a real battery-life gap here: the EarFun Uboom X is rated for 30 hours, the Harman Kardon Onyx Studio 9 only 8 hours.
Water resistance is not close: the EarFun Uboom X is rated at IP67 (brief submersion), well ahead of the Harman Kardon Onyx Studio 9 at no water resistance.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Prices on this page were last checked November 7, 2026 at 7:34 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
| EarFun Uboom X | Harman Kardon Onyx Studio 9 | |
|---|---|---|
| Price | $159.99 Discontinued | $184.99 |
| Ranked | #1 of 113 in Boombox Size Portable Bluetooth Speakers | #15 of 113 in Boombox Size Portable Bluetooth Speakers |
| App | Yes (Earfun Audio app) | Yes (Harman Kardon One app) |
| Aux Input | Yes | No |
| Aux Latency | 16ms | - |
| Bass Extension (-10dB) | ~38Hz | 41Hz |
| Battery Life | 30 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | AAC, SBC | SBC |
| Built-in Microphone | Yes | - |
| EQ | Yes (App EQ) | Yes (App EQ) |
| IP Rating | IP67 | None |
| Bluetooth Latency | SBC Video mode 48ms, AAC Video mode 128ms, SBC 112ms, AAC 176ms | - |
| Maximum SPL | 110dB (measured by Alan Ross Reviews) | 101dB (measured by Alan Ross Reviews) |
| Party Mode | Yes (Party Connect mode, up to 50 speakers) | Yes (Auracast) |
| Power Bank | Yes (USB-C) | - |
| Power Input | USB-C | AC Power Cable (2-Prong) |
| TWS | Yes | Yes |
| Weight | 9 lbs (4.1 kg) | 9.3 lbs (4.2 kg) |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| USB Playback | No | No |
| FM Tuner | No | - |
| Bluetooth Version | 5.3 | 5.3 |
| Amplifier Power | 80W | 50W RMS |
| Dimensions | 15.7” x 5.9” x 8.5” (400 x 150 x 215 mm) | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) |
| Drivers | 2x 102mm (4”) woofers + 2x 20mm tweeters | 120mm woofer + 3x 20mm tweeters |
| Digital Aux Input | No | No |
| Lights | Yes | - |
| Strap | Yes (detachable shoulder strap) | No |
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