Short answer: the JBL Partybox Encore Essential 2 for off-axis performance, the Onyx Studio 9 for connectivity. The Encore Essential 2 appears to have better off axis performance due to the move to dome tweeters over cone, though it is missing a little bit of upper bass. The Onyx Studio 9 adds Auracast multi-speaker connection alongside classic stereo pairing, but has slightly recessed mids, a boost in the upper mids and rolled off upper treble.
Buy the JBL Partybox Encore Essential 2. It is rated higher for sound quality, and saving $64.96 with the Harman Kardon Onyx Studio 9 does not make up for the sound-quality gap.
If battery life is a priority, the JBL Partybox Encore Essential 2 is rated for 15 hours versus 8 hours for the Harman Kardon Onyx Studio 9.
There is a real gap in water resistance: the JBL Partybox Encore Essential 2 at IPX4 (splashing) against the Harman Kardon Onyx Studio 9, which has 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 Partybox Encore Essential 2 | |
|---|---|---|
| Price | $184.99 | $249.95 |
| Ranked | #15 of 113 in Boombox Size Portable Bluetooth Speakers | #6 of 113 in Boombox Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | 41Hz | 42Hz |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) | 110dB (measured by Alan Ross Reviews) |
| IP Rating | None | IPX4 |
| 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) | 13.7 lbs (6.2 kg) |
| App | Yes (Harman Kardon One app) | Yes (JBL PartyBox app) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| EQ | Yes (App EQ) | Yes (7 band App EQ) |
| Party Mode | Yes (Auracast) | Yes (Auracast) |
| USB Playback | No | Yes |
| Bluetooth Version | 5.3 | 5.4 |
| Battery Life | 8 hours (Manufacturer specified) | 15 hours (Manufacturer specified) |
| Amplifier Power | 50W RMS | 100W RMS |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) | 12.6” x 13.5” x 10.3” (319.5 x 342 x 260.4 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters | 1x 135mm (5.25”) woofer + 2x 20mm (0.75”) dome tweeters |
| Digital Aux Input | No | No |
| Aux Input | No | Yes |
| Strap | No | No |
| Built-in Microphone | - | No |
| Guitar Input | - | Yes |
| Microphone Input | - | Yes (Karaoke mode with echo effect) |
| Power Bank | - | Yes (USB-C) |
| Wireless Microphones | - | No |
| Lights | - | Yes |
Related Speaker Comparisons
How JBL Partybox Encore Essential 2 compares with other leading options: