Short answer: both are discontinued, so this only matters if you are buying used. Used, the Harman Kardon Onyx Studio 6 is the better pick: it ranks #13 of 112 boombox speakers by sound quality (rated 4.1/5), against #74 (rated 2.8/5) for the Demerbox DB2. If you want one new, the Harman Kardon Onyx Studio 9 replaces the Harman Kardon Onyx Studio 6 and is rated 4.1/5 at $184.99.
The Harman Kardon Onyx Studio 6 is the better-sounding pick. A waterproof carry speaker with warm sound, deep bass for its size, and pairing with a second unit. It links with other speakers (Wireless Dual Sound), which the Demerbox DB2 cannot. The catch: Warm tuning with boosted bass, and not as loud as others.
The Demerbox DB2 is the longer-running choice. A nearly indestructible waterproof speaker built from a Pelican case, with a 40 hour battery and dry storage. It is rated for 40 hours of battery against 8 for the Harman Kardon Onyx Studio 6. It plays in stereo from a single unit, unlike the Harman Kardon Onyx Studio 6. The tradeoff: Bass is not as deep as better speakers.
Buy the Harman Kardon Onyx Studio 6 only if you find one used in good condition; both are discontinued, and it is the better rated of the two. For a new speaker, buy the Harman Kardon Onyx Studio 9, which replaces the Harman Kardon Onyx Studio 6.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
A waterproof carry speaker with warm sound, deep bass for its size, and pairing with a second unit.
A nearly indestructible waterproof speaker built from a Pelican case, with a 40 hour battery and dry storage.
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Specifications Side By Side
| Harman Kardon Onyx Studio 6 | Demerbox DB2 | |
|---|---|---|
| Price | $130 Discontinued | $400 Discontinued |
| Ranked | #13 of 112 in Boombox Size Portable Bluetooth Speakers | #74 of 112 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | 37Hz | - |
| Battery Life | 8 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| IP Rating | IPX7 | IP67 |
| Bluetooth Latency | 180ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | - |
| Party Mode | Yes (Wireless Dual Sound) | No |
| Power Input | DC Barrel Connector (19V/2A) | AC Power brick |
| Stereo | No | Yes |
| Omnidirectional | No | No |
| TWS | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) | Yes |
| Weight | 6.5 lbs (2.94 kg) | 5.4 lbs (2.47 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| App | No | No |
| EQ | No | No |
| Power Bank | No | Yes (USB-A + USB-C) |
| USB Playback | No | No |
| Bluetooth Version | 4.2 | - |
| Amplifier Power | 50W RMS | 22W RMS |
| Dimensions | 5” x 11.5” x 11.2” (128 x 291 x 284 mm) | 10.6” x 9.7” x 6.9” (270 x 246 x 175 mm) |
| Drivers | 1x 120mm (4.7”) woofer + 1x 25mm (1”) tweeter + 1x passive radiator | 2x 3” (76mm) aluminum cone full-range drivers |
| Digital Aux Input | No | No |
| Strap | No | - |
| FM Tuner | - | No |
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