Different classes, so treat this as a step-up-or-not question rather than a head-to-head. The Harman Kardon Onyx Studio 8 ranks #12 of 85 boombox speakers by sound quality at $179.99; the Zealot S79 ranks #41 of 83 large speakers by sound quality at $106.97.
These are built for different jobs. The Harman Kardon Onyx Studio 8 is a premium indoor design that sits well on furniture, while the Zealot S79 is rugged, loud and made to go outdoors.
In an indoor sound test listeners heard much deeper, cleaner bass from the Onyx Studio 8, with the Zealot a little louder but rougher. The Zealot’s bass boost mode can distort past about 70 percent volume.
The Zealot has the far bigger battery, a claimed 50+ hours against about 8, plus RGB lights, a shoulder strap and a power bank output. The Onyx is not water resistant, so it is a home speaker first.
Worth knowing: the Harman Kardon Onyx Studio 8 is discontinued, though it still ranks #12 of 85 boombox speakers by sound quality, so a used unit beats most of what is still sold new.
Buy the Harman Kardon Onyx Studio 8 ($179.99) for a boombox speaker; the Zealot S79 ($106.97) suits a large speaker instead.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 8 | Zealot S79 | |
|---|---|---|
| Price | $179.99 Discontinued | $106.97 |
| Ranked | #12 of 85 in Boombox Size Portable Bluetooth Speakers | #41 of 83 in Large Size Portable Bluetooth Speakers |
| Aux Input | Yes | - |
| Aux Latency | 42ms | - |
| Bass Extension (-10dB) | 35Hz | - |
| Battery Life | 8 hours (Manufacturer specified) | 50+ hours (Manufacturer specified) |
| Built-in Microphone | Yes | - |
| IP Rating | None | - |
| Bluetooth Latency | 175ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | - |
| Power Input | DC Barrel Connector (19V/2.1A) | - |
| Stereo | Partially (1 woofer) | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 7.3 lbs (3.3 kg) | 7.3 lbs (3.3 kg) |
| App | Yes (Harman Kardon One app) | - |
| Bluetooth Codecs | SBC | - |
| Power Bank | No | Yes |
| EQ | Yes (App EQ) | - |
| Party Mode | No | - |
| USB Playback | No | - |
| Bluetooth Version | 5.2 | 5.3 |
| Amplifier Power | 50W RMS | 100W (150W peak) |
| Dimensions | 10.6” x 11.9” x 6.3” (268 x 302.5 x 159.5 mm) | 13.4” x 7.2” x 5.7” (340 x 184 x 146 mm) |
| Drivers | 120mm woofer + 2x 20mm tweeters | 2 woofers + 2 tweeters |
| Digital Aux Input | No | - |
| Discontinued | Yes | - |
| Strap | No | Yes (detachable shoulder strap) |
| Lights | - | 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 Encore Essential 2 vs Harman Kardon Onyx Studio 8
- JBL Partybox Encore vs Harman Kardon Onyx Studio 8
Prices on this page were last checked September 26, 2026 at 11:14 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.
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The Two Speakers In Full
Harman Kardon Onyx Studio 8: $179.99 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 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) |
| Discontinued | Yes |
| 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
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- Harman Kardon Onyx Studio 8 vs Harman Kardon Onyx Studio 9
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- Harman Kardon Onyx Studio 8 vs JBL Partybox Encore Essential
- Harman Kardon Onyx Studio 8 vs Zealot ZE51
- See all 58 comparisons
Zealot S79: $106.97 Amazon eBay
Pros: Loud with plenty of bass and a wider soundstage than the JBL Xtreme 3, which it beats at full volume. A huge 24,000mAh battery with a claimed 50+ hours doubles as a power bank, and it adds RGB lights, a shoulder strap, EQ modes and stereo pairing.
Cons: At moderate volume the JBL Xtreme 3 is cleaner and more balanced, and one reviewer preferred the JBL Xtreme 4 in every way. Its bass boost mode sounds muddy and can distort past about 70% volume, so it is best left on the normal EQ. The Harman Kardon Onyx Studio 8 digs deeper in the bass. The evidence is listening comparisons, not measurements.
Full Zealot S79 review and specifications →
| Amplifier Power | 100W (150W peak) |
|---|---|
| Battery Life | 50+ hours (Manufacturer specified) |
| Bluetooth Version | 5.3 |
| Dimensions | 13.4” x 7.2” x 5.7” (340 x 184 x 146 mm) |
| Drivers | 2 woofers + 2 tweeters |
| Lights | Yes |
| Omnidirectional | No |
| Power Bank | Yes |
| Stereo | Yes |
| Strap | Yes (detachable shoulder strap) |
| TWS | Yes |
| Weight | 7.3 lbs (3.3 kg) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons