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.
Buy the Harman Kardon Onyx Studio 9. It is rated higher for sound quality, and the $35.04 you would save on the Gemini GRV-650L does not close the gap.
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.
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
| Gemini GRV-650L | Harman Kardon Onyx Studio 9 | |
|---|---|---|
| Price | $149.95 | $184.99 |
| Ranked | #56 of 113 in Boombox Size Portable Bluetooth Speakers | #15 of 113 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 | Yes | Yes |
| 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 |
| Strap | No | No |
Related Speaker Comparisons
How Harman Kardon Onyx Studio 9 compares with other leading options: