Short answer: the Harman Kardon Onyx Studio 9 on measured sound quality, the Zealot ZE01 on price. The Harman Kardon Onyx Studio 9 ranks #13 of 73 boombox speakers at $186.99. The Zealot ZE01 ranks #25 at $169.99, $17 cheaper.
What the Harman Kardon Onyx Studio 9 offers: Auracast multi-speaker connection alongside classic stereo pairing. Harman Kardon One app with EQ. USB-C charging, up from the previous generation’s AC power brick. Watch for: Slight recessed mids, boost in the upper mids, rolled off upper treble. Not as deep bass as previous Onyx Studio speakers.
What the Zealot ZE01 offers: Appears to be the same internals as the S95 Watch for: A little rolled off up top and not that balanced through the rest of the range. Clarity isn’t as good as better speakers.
Buy the Harman Kardon Onyx Studio 9 if sound quality is the priority over the price, or the Zealot ZE01 if the price is the priority over sound quality.
Battery life favors the Zealot ZE01: rated for 40 hours against 8 hours for the Harman Kardon Onyx Studio 9.
If water resistance matters to you, the Zealot ZE01 at IPX6 (powerful water jets) holds up far better than the Harman Kardon Onyx Studio 9 at no water resistance.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | Zealot ZE01 | |
|---|---|---|
| Price | $186.99 | $169.99 |
| Ranked | #13 of 73 in Boombox Size Portable Bluetooth Speakers | #25 of 73 in Boombox Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | 41Hz | 45Hz |
| Max Volume | 101dB | - |
| IP Rating | None | IPX6 |
| Power Input | AC Power Cable (2-Prong) | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 9.3 lbs / 4.2 kg | 13.2 lbs / 6.0 kg |
| App | Yes (Harman Kardon One app) | No |
| Bluetooth Codecs | SBC | SBC |
| EQ | Yes (App EQ) | Yes (multiple modes) |
| Party Mode | Yes (Auracast) | No |
| USB Playback | No | Yes |
| Bluetooth Version | 5.3 | - |
| Battery Life | 8 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Output Power | 50W RMS | 120W RMS / 150W peak |
| Dimensions | 11.4" x 11.3" x 5.1" (289.2 x 287.5 x 130 mm) | 13.1" x 11.2" x 8.1" (332 x 284 x 207 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters | Dual 120mm speakers + dual 42mm speakers |
| Digital Aux Input | No | No |
| Aux Input | - | Yes |
| MicroSD Playback | - | Yes |
| Power Bank | - | Yes (USB-A + USB-C) |
| Built in Microphone | - | No |
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Prices on this page were last checked August 27, 2026 at 10:09 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: $186.99 Amazon eBay
Pros: Auracast multi-speaker connection alongside classic stereo pairing. Harman Kardon One app with EQ. USB-C charging, up from the previous generation’s AC power brick.
Cons: Slight recessed mids, boost in the upper mids, rolled off upper treble. Not as deep bass as previous Onyx Studio speakers.
Full Harman Kardon Onyx Studio 9 review and specifications →
| App | Yes (Harman Kardon One app) |
|---|---|
| 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 |
| Max Volume | 101dB |
| Omnidirectional | No |
| Output Power | 50W RMS |
| Party Mode | Yes (Auracast) |
| Power Input | AC Power Cable (2-Prong) |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | No |
| Weight | 9.3 lbs / 4.2 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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- Harman Kardon Onyx Studio 9 vs Harman Kardon Onyx Studio 7
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- Harman Kardon Onyx Studio 9 vs Zealot S89
- Harman Kardon Onyx Studio 9 vs Harman Kardon Onyx Studio 8
- Harman Kardon Onyx Studio 9 vs JBL Boombox 4
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Zealot ZE01: $169.99 Amazon Aliexpress eBay
Pros: Appears to be the same internals as the S95
Cons: A little rolled off up top and not that balanced through the rest of the range. Clarity isn’t as good as better speakers.
Full Zealot ZE01 review and specifications →
| App | No |
|---|---|
| Aux Input | Yes |
| Bass Extension (-10dB) | 45Hz |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Built in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 13.1" x 11.2" x 8.1" (332 x 284 x 207 mm) |
| Drivers | Dual 120mm speakers + dual 42mm speakers |
| EQ | Yes (multiple modes) |
| IP Rating | IPX6 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Output Power | 120W RMS / 150W peak |
| Party Mode | No |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 13.2 lbs / 6.0 kg |
- Links
- Reviews, Comparisons and Sound Samples
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