Short answer: the Onyx Studio 9. It ranks #15 of 76 boombox speakers at $189.99, well ahead of the Onyx Studio 4’s #50 of 82 large speakers at $100. Five generations separate them, and it shows.
Worth knowing: the Harman Kardon Onyx Studio 4 has been discontinued and is hard to find new at this point.
The Studio 9 modernizes what the Studio 4 got right. Both keep the same round twin-orb silhouette and stereo pairing, but the Studio 9 adds Auracast for connecting multiple speakers together, an app with EQ control, and USB-C charging in place of the Studio 4’s external AC power brick. Its driver layout also changed, from the Studio 4’s two 75mm woofers and two 20mm tweeters to a single 120mm woofer with three 20mm tweeters.
Neither speaker is without a sound tradeoff. The Studio 4’s own notes praise its balanced sound and deep resonant bass but flag it as not as loud as others. The Studio 9’s notes describe a slight recessed midrange, a boost in the upper mids, and rolled-off upper treble, plus bass that isn’t quite as deep as earlier Onyx Studio models. If deep bass matters most to you, that’s the one place the older speaker still has an edge on paper, according to Harman Kardon’s own comparison notes between generations.
Buy the Harman Kardon Onyx Studio 9 for the current Auracast connectivity, app-based EQ, and USB-C charging, and because it ranks well ahead of the Studio 4 in its own class.
Buy the Harman Kardon Onyx Studio 4 only if you find one secondhand and specifically prefer its bass response; it’s no longer sold new.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 4 | Harman Kardon Onyx Studio 9 | |
|---|---|---|
| Price | $100 Discontinued | $189.99 |
| Ranked | #50 of 82 in Large Size Portable Bluetooth Speakers | #15 of 76 in Boombox Size Portable Bluetooth Speakers |
| App | Yes (HK Connect) | Yes (Harman Kardon One app) |
| Aux Input | Yes | No |
| Battery Life | 8 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| EQ | No | Yes (App EQ) |
| IP Rating | None | None |
| Party Mode | Yes (Connect+ up to 100 speakers) | Yes (Auracast) |
| Power Bank | No | - |
| TWS | Yes | Yes |
| Weight | 4.5 lbs (2.06 kg) | 9.3 lbs (4.2 kg) |
| Bluetooth Codecs | SBC | SBC |
| Built-in Microphone | Yes | - |
| Power Input | DC Barrel Connector (19V/2.1A) | AC Power Cable (2-Prong) |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Bluetooth Version | 4.2 | 5.3 |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters + 1x passive radiator | 120mm woofer + 3x 20mm tweeters |
| Dimensions | 11.4” x 11.4” x 5.1” (290 x 290 x 130 mm) | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 60W | 50W RMS |
| Discontinued | Yes | - |
| Digital Aux Input | No | No |
| Strap | No | No |
| Bass Extension (-10dB) | - | 41Hz |
| Maximum SPL | - | 101dB (measured by Alan Ross Reviews) |
| USB Playback | - | No |
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Prices on this page were last checked September 26, 2026 at 11:14 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 4: $100 Discontinued eBay
Newer model: the Harman Kardon Onyx Studio 9, rated 4.1/5.
Pros: Balanced sound quality with deep resonant bass and crisp treble, large dynamic range. Multi-host Bluetooth connectivity for 2 phones, daisy chaining up to 100 speakers. Elegant modern design with smooth curves and premium materials.
Cons: 8 hour battery at medium volume. Not at loud as others. Not as deep of bass as the newer Onyx. External AC power brick for charging. Discontinued.
Full Harman Kardon Onyx Studio 4 review and specifications →
| Amplifier Power | 60W |
|---|---|
| App | Yes (HK Connect) |
| Aux Input | Yes |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.4” x 11.4” x 5.1” (290 x 290 x 130 mm) |
| Discontinued | Yes |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters + 1x passive radiator |
| EQ | No |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) |
| IP Rating | None |
| Omnidirectional | No |
| Party Mode | Yes (Connect+ up to 100 speakers) |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2.1A) |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| Weight | 4.5 lbs (2.06 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 4 vs Zealot S97
- Harman Kardon Onyx Studio 4 vs JBL Xtreme 2
- Harman Kardon Onyx Studio 4 vs Tronsmart Halo 100
- Harman Kardon Onyx Studio 4 vs W-King D8
- Harman Kardon Onyx Studio 4 vs Sony SRS-XB43
- Harman Kardon Onyx Studio 4 vs JBL Xtreme
- Harman Kardon Onyx Studio 4 vs Doss Soundbox XL
- Harman Kardon Onyx Studio 4 vs Sony ULT Field 5
- See all 38 comparisons
Harman Kardon Onyx Studio 9: $189.99 Amazon eBay
Older models: the Harman Kardon Onyx Studio 8 (rated 4.1/5), the Harman Kardon Onyx Studio 7 (rated 4.1/5), the Harman Kardon Onyx Studio 6 (rated 4.1/5), the Harman Kardon Onyx Studio 5 (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 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
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- Harman Kardon Onyx Studio 9 vs Zealot ZE21
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