Short answer: the Gemini GRV-650L for value, the Harman Kardon Onyx Studio 9 for features. The Gemini is pretty amazing value for the money, though its bass is not quite as deep as the top ranked speakers. The Onyx adds Auracast multi-speaker connection alongside classic stereo pairing, but its mids are slightly recessed with a boost in the upper mids and rolled off upper treble.
On the Gemini GRV-650L side: Pretty amazing value for the money. The catch: Not quite as deep bass as the top ranked speakers.
The case for the Harman Kardon Onyx Studio 9: Auracast multi-speaker connection alongside classic stereo pairing. The catch: Slight recessed mids, boost in the upper mids, rolled off upper treble.
Buy the Gemini GRV-650L when the price outweighs sound quality for you, and the Harman Kardon Onyx Studio 9 when sound quality outweighs the price instead.
There is a real gap in water resistance: the Gemini GRV-650L at IPX5 (water jets) against the Harman Kardon Onyx Studio 9, which has no water resistance.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Gemini GRV-650L | Harman Kardon Onyx Studio 9 | |
|---|---|---|
| Price | $149.95 | $189.99 |
| Ranked | #38 of 75 in Boombox Size Portable Bluetooth Speakers | #14 of 75 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | No |
| Bass Extension (-10dB) | ~47Hz | 41Hz |
| Battery Life | 9 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| MicroSD Playback | Yes | - |
| Power Bank | Yes | - |
| Stereo | Partially (1 woofer) | Yes |
| Omnidirectional | No | No |
| USB Playback | Yes | No |
| Weight | 15.7 lbs (7.1 kg) | 9.3 lbs (4.2 kg) |
| Bluetooth Codecs | SBC | SBC |
| App | No | Yes (Harman Kardon One app) |
| EQ | No | Yes (App EQ) |
| TWS | Yes | Yes |
| Party Mode | No | Yes (Auracast) |
| Built-in Microphone | No | - |
| Power Input | USB-C | AC Power Cable (2-Prong) |
| FM Tuner | Yes | - |
| Amplifier Power | 320W | 50W RMS |
| Dimensions | 10.9" x 10.2" x 14.4" (277 x 260 x 366 mm) | 11.4" x 11.3" x 5.1" (289.2 x 287.5 x 130 mm) |
| Drivers | 6.5" woofer + tweeter | 120mm woofer + 3x 20mm tweeters |
| IP Rating | IPX5 | None |
| Maximum SPL | 104dB (Manufacturer specified) | 101dB (measured by Alan Ross Reviews) |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.3 | 5.3 |
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- Harman Kardon Onyx Studio 9 vs JBL Partybox Encore Essential 2
Prices on this page were last checked September 22, 2026 at 5:11 AM 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
Gemini GRV-650L: $149.95 Amazon eBay
Pros: Pretty amazing value for the money. Decently deep bass, not quite as good as top ranked speakers. Included wireless microphone and remote control. Measured bass extension of ~47Hz (-10dB).
Cons: Not quite as deep bass as the top ranked speakers.
Full Gemini GRV-650L review and specifications →
| Amplifier Power | 320W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | ~47Hz |
| Battery Life | 9 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 10.9" x 10.2" x 14.4" (277 x 260 x 366 mm) |
| Drivers | 6.5" woofer + tweeter |
| EQ | No |
| FM Tuner | Yes |
| IP Rating | IPX5 |
| Maximum SPL | 104dB (Manufacturer specified) |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | Yes |
| Power Input | USB-C |
| Stereo | Partially (1 woofer) |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 15.7 lbs (7.1 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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
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