Short answer: the Harman Kardon Onyx Studio 9, if you are buying new. The Harman Kardon Onyx Studio 8 ranks higher than the Zealot S78 (#12 vs #97 of 98 boombox speakers) but is discontinued; its replacement, the Harman Kardon Onyx Studio 9, is rated 4.1/5 at $189.99 and is still sold new.
The Harman Kardon Onyx Studio 8 is the better-sounding, lighter option. Claimed 8 hours (manufacturer specified) battery life and up to 96db make its feature set practical for its intended room or portable use. At 7.3 lbs (3.3 kg) it weighs noticeably less than the Zealot S78 at 9.7 lbs (4.4 kg). The catch: Warm tuning with boosted bass, not as loud as others, and no water resistance rating.
The Zealot S78 is the longer-running, tougher choice. A robust 9.7 lbs (4.4 kg) party speaker with claimed 120W RMS output, IP67 protection, USB-C charging, a power-bank function, aux, USB and microSD playback, TWS pairing and multiple EQ modes. It is rated for 40 hours of battery against 8 for the Harman Kardon Onyx Studio 8. It is rated IP67, while the Harman Kardon Onyx Studio 8 has no water resistance. The tradeoff: At high volume, reviews report distortion and fluctuating level, so its headline power is more useful below its maximum setting.
Buy the Harman Kardon Onyx Studio 9, the replacement for the discontinued Harman Kardon Onyx Studio 8; it is rated higher for sound quality than the Zealot S78.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Harman Kardon Onyx Studio 8 | Zealot S78 | |
|---|---|---|
| Price | $199.00 Discontinued | $159.68 |
| Ranked | #12 of 98 in Boombox Size Portable Bluetooth Speakers | #97 of 98 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Aux Latency | 42ms | - |
| Bass Extension (-10dB) | 35Hz | - |
| Battery Life | 8 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| IP Rating | None | IP67 |
| 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) | 9.7 lbs (4.4 kg) |
| App | Yes (Harman Kardon One app) | No |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Power Bank | No | Yes (USB-A) |
| EQ | Yes (App EQ) | Yes (multiple modes) |
| Party Mode | No | No |
| USB Playback | No | Yes |
| Bluetooth Version | 5.2 | 5.3 |
| Amplifier Power | 50W RMS | 120W RMS / 150W peak |
| Dimensions | 10.6” x 11.9” x 6.3” (268 x 302.5 x 159.5 mm) | 16.1” x 6.6” x 7.3” (410 x 167 x 185 mm) |
| Drivers | 120mm woofer + 2x 20mm tweeters | 2x ~120mm (4.72”) woofers + 2x ~42mm tweeters + 2x passive radiators |
| Digital Aux Input | No | No |
| Strap | No | Yes (detachable shoulder strap) |
| MicroSD Playback | - | Yes |
Related Speaker Comparisons
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- 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 October 12, 2026 at 4:13 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: $199.00 Discontinued Amazon $199.00 eBay
Newer model: the Harman Kardon Onyx Studio 9, ranked lower, rated 4.1/5, released Dec 2024. It adds party mode, but drops the aux input.
Older models: the Harman Kardon Onyx Studio 7 (ranked lower, rated 4.1/5), the Harman Kardon Onyx Studio 6 (ranked lower, rated 4.1/5), the Harman Kardon Onyx Studio 5 (ranked lower, rated 3.9/5) and the Harman Kardon Onyx Studio 4 (rated 3.3/5). See every Harman Kardon Onyx Studio generation.
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 →
| Released | Sep 2022 (4 years ago) |
|---|---|
| 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: Dead room vs Live room - Onyx studio 8 self tuning test! part 1 of 3
- 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 - The Anti Shill!: 3 tweeters, Auracast, whats not to like! This is shocking!
- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers!
- YARNZO Tech: Zealot S79 vs Onyx Studio 8 (indoor sound test) More from YARNZO Tech →
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- See all 80 comparisons
Zealot S78: $159.68 Amazon $159.68 AliExpress $91.38 eBay
Pros: A robust 4.4kg party speaker with claimed 120W RMS output, IP67 protection, USB-C charging, a power-bank function, aux, USB and microSD playback, TWS pairing and multiple EQ modes. Reviews find it very loud with useful bass and long claimed battery life, making it a credible choice for outdoor gatherings.
Cons: At high volume, reviews report distortion and fluctuating level, so its headline power is more useful below its maximum setting. It has no app-based EQ, and the bass and midrange refinement do not match better-established boombox speakers; assess its sound in person if tonal accuracy matters.
Full Zealot S78 review and specifications →
| Released | May 2023 (3 years ago) |
|---|---|
| Amplifier Power | 120W RMS / 150W peak |
| App | No |
| Aux Input | Yes |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.1” x 6.6” x 7.3” (410 x 167 x 185 mm) |
| Drivers | 2x ~120mm (4.72”) woofers + 2x ~42mm tweeters + 2x passive radiators |
| EQ | Yes (multiple modes) |
| IP Rating | IP67 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | Yes (USB-A) |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | Yes (detachable shoulder strap) |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 9.7 lbs (4.4 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Jay’s Straight Up Reviews & More: DBSOARS F29 Max vs Zealot S78 🛜 (5B) Budget Bluetooth Boombox Basement Battle 🔊 Bass Modes Enabled More from JaysStraightUpReviews →
- Jay’s Straight Up Reviews & More: W-King X20 vs Zealot S78 Bluetooth Boombox Battle Outdoor Tailgater Special 🚗 Let the Whoopin’ Begin
- Head-to-Head Comparisons