Short answer: the Onyx Studio 9, for a third of the price. It adds Auracast multi-speaker connection, USB-C charging and an EQ-capable app, with only slightly recessed mids and rolled-off upper treble as tradeoffs. The Boombox 4 has pretty insane output capability for its size, but it is pretty overpriced for the category and out of the box it sounds worse than the older Boombox 3.
Buy the Harman Kardon Onyx Studio 9. It is rated higher for sound quality than the JBL Boombox 4 and costs less, so the other one has nothing left to offer.
If battery life is a priority, the JBL Boombox 4 is rated for 28 hours versus 8 hours for the Harman Kardon Onyx Studio 9.
Water resistance is not close: the JBL Boombox 4 is rated at IP68 (extended submersion), well ahead of the Harman Kardon Onyx Studio 9 at no water resistance.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | JBL Boombox 4 | |
|---|---|---|
| Price | $189.99 | $549.95 |
| Ranked | #14 of 75 in Boombox Size Portable Bluetooth Speakers | #19 of 75 in Boombox Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | 41Hz | 41Hz |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) | 115dB (measured by Alan Ross Reviews) |
| IP Rating | None | IP68 |
| Power Input | AC Power Cable (2-Prong) | AC Power cord |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 9.3 lbs (4.2 kg) | 13.2 lbs (5.98 kg) |
| App | Yes (Harman Kardon One app) | Yes |
| Bluetooth Codecs | SBC | SBC, LC3, AAC |
| EQ | Yes (App EQ) | Yes (7 band) |
| Party Mode | Yes (Auracast) | Yes (Auracast) |
| USB Playback | No | No |
| Bluetooth Version | 5.3 | 5.4 |
| Battery Life | 8 hours (Manufacturer specified) | 28 hours (Manufacturer specified) |
| Amplifier Power | 50W RMS | 210W AC / 200W battery |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) | 20.1” x 10.2” x 8.3” (510 x 260 x 210 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters | 2x 123mm woofers + 2x 20mm tweeters with passive radiators |
| Digital Aux Input | No | Yes (USB-C) |
| Aux Input | No | No |
| Bluetooth Latency | - | AAC 144ms, SBC 48ms |
| Removable Battery | - | Yes |
| Built-in Microphone | - | No |
| Power Bank | - | Yes (USB-C, up to 30W) |
| FM Tuner | - | No |
| Microphone Input | - | No |
| MicroSD Playback | - | No |
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 24, 2026 at 10:28 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.
As an eBay Partner, we may be compensated if you make a purchase.
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
- 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 64 comparisons
JBL Boombox 4: $549.95 Amazon B&H Photo Video eBay
Pros: Pretty insane output capability for the size. IP68 protection and Auracast pairing with other current JBL speakers. Measured bass extension of 41Hz (-10dB).
Cons: Pretty overpriced for the category. Better than the Boombox 3 mostly because there are more 7 EQ bands instead of just 3 and it can be better tuned. Try Oluv’s EQ for it. Out of the box sounds worse than the Boombox 3. No Aux input.
Full JBL Boombox 4 review and specifications →
| Amplifier Power | 210W AC / 200W battery |
|---|---|
| App | Yes |
| Aux Input | No |
| Bass Extension (-10dB) | 41Hz |
| Battery Life | 28 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC, LC3, AAC |
| Bluetooth Latency | AAC 144ms, SBC 48ms |
| Bluetooth Version | 5.4 |
| Built-in Microphone | No |
| Digital Aux Input | Yes (USB-C) |
| Dimensions | 20.1” x 10.2” x 8.3” (510 x 260 x 210 mm) |
| Drivers | 2x 123mm woofers + 2x 20mm tweeters with passive radiators |
| EQ | Yes (7 band) |
| FM Tuner | No |
| IP Rating | IP68 |
| Maximum SPL | 115dB (measured by Alan Ross Reviews) |
| MicroSD Playback | No |
| Microphone Input | No |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Bank | Yes (USB-C, up to 30W) |
| Power Input | AC Power cord |
| Removable Battery | Yes |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | No |
| Weight | 13.2 lbs (5.98 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Boombox 3 - old one sounding better? 🤔 More from Oluv’Sone →
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Earfun UBoom X - sound test
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Boombox 3 - any improvement?
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Partybox Encore 2 - outdoor loudness & basstest
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 - finally a real BOOMbox from JBL 👏
- Alan Ross Reviews: JBL Boombox 4 HUMILIATES Brane X?! Ultimate Bass Battle! More from alanrossreviews →
- Alan Ross Reviews: JBL Boombox 4 Compared to Boombox 3 & 3 WiFi – Worth the Upgrade?
- Alan Ross Reviews: JBL Boombox 4 distortion fest bonanza! how bad can it be lol 🤣
- Jagist reviews: Jbl Boombox 4 Vs Zealot Ze21!!! More from Jagistreviews →
- Techder Audios: JBL Boombox 4 VS Zealot ZE21 BATTLE OF THE BOOMBOXES! More from techderaudios →
- Dominik Reviews: Zealot S89 vs JBL Boombox 4 - JBL Alternative? Sound Test More from Dominik Reviews →
- Jagist reviews: Jbl Boombox 4 Vs Zealot S89!!!
- Jagist reviews: Jbl Boombox 4 Vs Zealot S95!!!
- M1MTechChannel: Welche JBL Partybox ist die BESTE ? Alle Partyboxen im Vergleich | 2026 More from M1MTechChannel →
- M1MTechChannel: JBL BOOMBOX 4 - Einfach komplett GEISTESKRANK
- Head-to-Head Comparisons