Short answer: the Harman Kardon Onyx Studio 9. It ranks #14 of 75 boombox speakers at $189.99 against the Yeahbox Sonic Boom Max 3’s #40, and it offers Auracast multi-speaker connection alongside classic stereo pairing. Its mids are slightly recessed with a lift in the upper mids and a rolled-off top end; the Yeahbox claims a 200W RMS three-way array, but comes from a budget import brand with limited independent testing.
What the Harman Kardon Onyx Studio 9 gets right: Auracast multi-speaker connection alongside classic stereo pairing. The tradeoff: Slight recessed mids, boost in the upper mids, rolled off upper treble.
On the Yeahbox Sonic Boom Max 3 side: 200W RMS (300W peak) true 3-way, 5-driver array. The tradeoff: A budget import brand with limited independent testing - specs are manufacturer-claimed.
Buy the Harman Kardon Onyx Studio 9. It ranks higher for sound quality than the Yeahbox Sonic Boom Max 3 and costs less, so there is no real case for the other one.
Water resistance is not close: the Yeahbox Sonic Boom Max 3 is rated at IPX6 (powerful water jets), well ahead of the Harman Kardon Onyx Studio 9 at no water resistance.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | Yeahbox Sonic Boom Max 3 | |
|---|---|---|
| Price | $189.99 | $206.09 |
| Ranked | #14 of 75 in Boombox Size Portable Bluetooth Speakers | #40 of 75 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) | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 9.3 lbs (4.2 kg) | 16.8 lbs (7.64 kg) |
| App | Yes (Harman Kardon One app) | Yes |
| Bluetooth Codecs | SBC | SBC (inferred; additional codecs unverified) |
| EQ | Yes (App EQ) | Yes |
| Party Mode | Yes (Auracast) | - |
| USB Playback | No | Yes |
| Bluetooth Version | 5.3 | 5.3 |
| Battery Life | 8 hours (Manufacturer specified) | 111Wh (14.8V/7,500mAh) (Manufacturer specified) |
| Amplifier Power | 50W RMS | 200W RMS / 300W Peak |
| Dimensions | 11.4" x 11.3" x 5.1" (289.2 x 287.5 x 130 mm) | 20.7" x 8.3" x 10.6" (525 x 210 x 268 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters | 189x114mm woofer, 2x 89mm midrange, 2x 38mm tweeters |
| Digital Aux Input | No | No |
| Aux Input | No | Yes |
| MicroSD Playback | - | Yes |
| Lights | - | 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
- Harman Kardon Onyx Studio 9 vs JBL Partybox Encore Essential 2
Prices on this page were last checked September 23, 2026 at 11:24 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
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 |
| TWS | Yes |
| USB Playback | No |
| Weight | 9.3 lbs (4.2 kg) |
- Links
- Reviews, Comparisons and Sound Samples
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Yeahbox Sonic Boom Max 3: $206.09 Amazon eBay
Pros: A large 3-way, 5-driver party speaker with claimed 200W RMS output, a 111Wh battery, USB-C fast charging, app EQ, TWS pairing, and aux, USB and microSD playback. Listener comparisons describe powerful bass, strong output and decent mids and highs for outdoor party use.
Cons: There is limited independent testing and the water/dust rating is reported inconsistently across listings. Listener comparisons find it less clear and refined than stronger boombox rivals, so its big bass and output are a better fit for parties than critical listening.
Full Yeahbox Sonic Boom Max 3 review and specifications →
| Amplifier Power | 200W RMS / 300W Peak |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Battery Life | 111Wh (14.8V/7,500mAh) (Manufacturer specified) |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 20.7" x 8.3" x 10.6" (525 x 210 x 268 mm) |
| Drivers | 189x114mm woofer, 2x 89mm midrange, 2x 38mm tweeters |
| EQ | Yes |
| IP Rating | IPX6 |
| Lights | Yes |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 16.8 lbs (7.64 kg) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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