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 Aiwa Exos-10 ranks #38, rated 3.5/5, at $159.99, $30 cheaper, not enough of a saving to outweigh the sound-quality gap.
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.
What the Aiwa Exos-10 does well: Clear, clean treble with good separation of instruments and vocals, and no distortion even near full volume in a side by side test against the W-King X20, where it kept up in loudness at 90%. Watch for: It lacks deep bass: even with bass maxed it rolls off around 50Hz, where the W-King X20 and Zealot boomboxes reach deeper, and it is about 2dB quieter at full volume.
Buy the Harman Kardon Onyx Studio 9. It is rated higher for sound quality, and saving $30 with the Aiwa Exos-10 does not make up for the sound-quality gap.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | Aiwa Exos-10 | |
|---|---|---|
| Price | $189.99 | $159.99 |
| Ranked | #15 of 89 in Boombox Size Portable Bluetooth Speakers | #38 of 89 in Boombox Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | 41Hz | - |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) | - |
| IP Rating | None | - |
| Power Input | AC Power Cable (2-Prong) | - |
| Stereo | Yes | Partially |
| Omnidirectional | No | - |
| TWS | Yes | - |
| Weight | 9.3 lbs (4.2 kg) | - |
| App | Yes (Harman Kardon One app) | - |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | - |
| EQ | Yes (App EQ) | Yes (bass and treble) |
| Party Mode | Yes (Auracast) | Yes (Party Sync, 100+ speakers) |
| USB Playback | No | Yes |
| Bluetooth Version | 5.3 | 5.0 |
| Battery Life | 8 hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| Amplifier Power | 50W RMS | 200W RMS (40W x 2 + 120W) |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) | - |
| Drivers | 120mm woofer + 3x 20mm tweeters | 6.5” (165mm) subwoofer + full-range drivers, 4 passive radiators |
| Digital Aux Input | No | - |
| Aux Input | No | Yes |
| Strap | No | - |
| Removable Battery | - | No |
| FM Tuner | - | Yes |
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
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 9 vs Harman Kardon Onyx Studio 7
- Harman Kardon Onyx Studio 9 vs Zealot ZE51
- Harman Kardon Onyx Studio 9 vs Zealot ZE41
- Harman Kardon Onyx Studio 9 vs Harman Kardon Onyx Studio 6
- Harman Kardon Onyx Studio 9 vs Zealot ZE21
- Harman Kardon Onyx Studio 9 vs Harman Kardon Onyx Studio 8
- Harman Kardon Onyx Studio 9 vs Zealot S89
- Harman Kardon Onyx Studio 9 vs Yeahbox Sonic Boom Ultra
- See all 93 comparisons
Aiwa Exos-10: $159.99 Amazon eBay
Older model: the Aiwa Exos-9 (ranked higher, rated 4.2/5).
Pros: Clear, clean treble with good separation of instruments and vocals, and no distortion even near full volume in a side by side test against the W-King X20, where it kept up in loudness at 90%. A 200W RMS tri-amplified design with a 6.5” woofer and four passive radiators, FM radio with presets, aux and USB inputs, a remote, analog-style VU meters and Party Sync with 100+ speakers.
Cons: It lacks deep bass: even with bass maxed it rolls off around 50Hz, where the W-King X20 and Zealot boomboxes reach deeper, and it is about 2dB quieter at full volume. Owners comparing it with the Aiwa Exos 9 it replaces find the older model clearer with tighter bass, and the Exos 10 drops the Exos 9’s 5-band EQ (only bass and treble) and removable battery. Claimed battery life is 12 hours.
Full Aiwa Exos-10 review and specifications →
| Amplifier Power | 200W RMS (40W x 2 + 120W) |
|---|---|
| Aux Input | Yes |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Version | 5.0 |
| Drivers | 6.5” (165mm) subwoofer + full-range drivers, 4 passive radiators |
| EQ | Yes (bass and treble) |
| FM Tuner | Yes |
| Party Mode | Yes (Party Sync, 100+ speakers) |
| Removable Battery | No |
| Stereo | Partially |
| USB Playback | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons