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, which makes it the one to get unless you need something the other one does better.
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.
Prices on this page were last checked November 7, 2026 at 7:34 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.
Specifications Side By Side
| Harman Kardon Onyx Studio 9 | JBL Boombox 4 | |
|---|---|---|
| Price | $184.99 | $549.95 |
| Ranked | #15 of 113 in Boombox Size Portable Bluetooth Speakers | #20 of 113 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 | Yes | 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 |
| Strap | 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: