Short answer: the Gemini GGO-650L, if you are buying new. The Harman Kardon Onyx Studio 8 ranks higher than it (#12 vs #73 of 89 boombox speakers, 4.1/5 vs 2.5/5) but is discontinued, so only consider it used; the Gemini GGO-650L is still sold new at $99.95.
What the Harman Kardon Onyx Studio 8 does well: At 3.3 kg, Harman Kardon Onyx Studio 8 combines a 120mm woofer and 2x 20mm tweeters with Bluetooth and aux. The tradeoff: Bass is limited by its 35Hz specification.
What the Gemini GGO-650L does well: At 4.2 kg, Gemini GGO-650L combines 6.5” woofer + tweeter with Bluetooth and aux. The tradeoff: Bass is limited by its ~56Hz specification.
Buy the Gemini GGO-650L, since the Harman Kardon Onyx Studio 8 is discontinued and only worth hunting down used.
There is a real gap in water resistance: the Gemini GGO-650L at IPX5 (water jets) against the Harman Kardon Onyx Studio 8, which has no water resistance.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Harman Kardon Onyx Studio 8 | Gemini GGO-650L | |
|---|---|---|
| Price | $197.90 Discontinued | $99.95 |
| Ranked | #12 of 89 in Boombox Size Portable Bluetooth Speakers | #73 of 89 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Aux Latency | 42ms | - |
| Bass Extension (-10dB) | 35Hz | ~56Hz |
| Battery Life | 8 hours (Manufacturer specified) | 10 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| IP Rating | None | IPX5 |
| Bluetooth Latency | 175ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | - |
| Power Input | DC Barrel Connector (19V/2.1A) | USB-C |
| Stereo | Partially (1 woofer) | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 7.3 lbs (3.3 kg) | 9.3 lbs (4.2 kg) |
| App | Yes (Harman Kardon One app) | No |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Power Bank | No | No |
| EQ | Yes (App EQ) | No |
| Party Mode | No | No |
| USB Playback | No | Yes |
| Bluetooth Version | 5.2 | 5.3 |
| Amplifier Power | 50W RMS | 100W |
| Dimensions | 10.6” x 11.9” x 6.3” (268 x 302.5 x 159.5 mm) | 11.8” x 9.1” x 15” (300 x 230 x 380 mm) |
| Drivers | 120mm woofer + 2x 20mm tweeters | 6.5” woofer + tweeter |
| Digital Aux Input | No | No |
| Strap | No | - |
| MicroSD Playback | - | Yes |
| FM Tuner | - | Yes |
Related Speaker Comparisons
How Harman Kardon Onyx Studio 8 compares with other leading options:
- Tribit Stormbox Blast vs Harman Kardon Onyx Studio 8
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 8
- JBL Partybox Encore 2 vs Harman Kardon Onyx Studio 8
- JBL PartyBox On-The-Go 2 Plus vs Harman Kardon Onyx Studio 8
- JBL Partybox Encore Essential 2 vs Harman Kardon Onyx Studio 8
Prices on this page were last checked September 30, 2026 at 2:57 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.
The Two Speakers In Full
Harman Kardon Onyx Studio 8: $197.90 Discontinued Amazon eBay
Newer model: the Harman Kardon Onyx Studio 9, ranked lower, rated 4.1/5.
Pros: At 3.3 kg, Harman Kardon Onyx Studio 8 combines a 120mm woofer and 2x 20mm tweeters with Bluetooth and aux. Claimed 8 hours (manufacturer specified) battery life and up to 96db make its feature set practical for its intended room or portable use. A built-in microphone and the Harman Kardon One app with EQ. Measured bass extension of 35Hz (-10dB).
Cons: Bass is limited by its 35Hz specification. Warm tuning with boosted bass, not as loud as others, and no water resistance rating. Discontinued.
Full Harman Kardon Onyx Studio 8 review and specifications →
| Amplifier Power | 50W RMS |
|---|---|
| App | Yes (Harman Kardon One app) |
| Aux Input | Yes |
| Aux Latency | 42ms |
| Bass Extension (-10dB) | 35Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 175ms |
| Bluetooth Version | 5.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 10.6” x 11.9” x 6.3” (268 x 302.5 x 159.5 mm) |
| Drivers | 120mm woofer + 2x 20mm tweeters |
| EQ | Yes (App EQ) |
| IP Rating | None |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2.1A) |
| Stereo | Partially (1 woofer) |
| Strap | No |
| TWS | Yes |
| USB Playback | No |
| Weight | 7.3 lbs (3.3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Harman Kardon Onyx Studio 8 review - part 2 of 3 More from alanrossreviews →
- Alan Ross Reviews: Onyx Studio 8 vs HK Onyx 6, Xtreme 3, PartyBox Encore, Go+ Play, Bag of Riddim! part 3 of 3
- Alan Ross Reviews: Dead room vs Live room - Onyx studio 8 self tuning test! part 1 of 3
- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers!
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 8 vs Harman Kardon Onyx Studio 6
- Harman Kardon Onyx Studio 8 vs Yeahbox Sonic Boom Ultra
- Harman Kardon Onyx Studio 8 vs Harman Kardon Onyx Studio 7
- Harman Kardon Onyx Studio 8 vs Vifa Copenhagen 2.0
- Harman Kardon Onyx Studio 8 vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 8 vs Aiwa Exos-9
- Harman Kardon Onyx Studio 8 vs JBL Partybox Encore Essential
- Harman Kardon Onyx Studio 8 vs Zealot ZE51
- See all 74 comparisons
Gemini GGO-650L: $99.95 Amazon eBay
Pros: At 4.2 kg, Gemini GGO-650L combines 6.5” woofer + tweeter with Bluetooth and aux. Claimed 10 hours (manufacturer specified) battery life, ipx5 protection and stereo playback make its feature set practical for its intended room or portable use. Measured bass extension of ~56Hz (-10dB).
Cons: Bass is limited by its ~56Hz specification. There is no companion app. No EQ adjustment.
Full Gemini GGO-650L review and specifications →
| Amplifier Power | 100W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | ~56Hz |
| Battery Life | 10 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.8” x 9.1” x 15” (300 x 230 x 380 mm) |
| Drivers | 6.5” woofer + tweeter |
| EQ | No |
| FM Tuner | Yes |
| IP Rating | IPX5 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 9.3 lbs (4.2 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons