Short answer: the Harman Kardon Onyx Studio 7. It ranks #14 of 98 boombox speakers by sound quality, rated 4.1/5, at $248.90. The Zealot S78 ranks #97, rated 2.0/5, at $159.68, $89.22 cheaper, which does not close the gap in sound quality.
The Harman Kardon Onyx Studio 7 is the better-sounding, lighter option. The addition of dual tweeters gives the Studio 7 a wider, more spacious presentation than older Onyx models. At 6.4 lbs (2.9 kg) it weighs noticeably less than the Zealot S78 at 9.7 lbs (4.4 kg). It links with other speakers (Wireless Dual Sound), which the Zealot S78 cannot. The catch: Consumer Reports finds the bass prominent and boomy, mids hazy, treble slightly smeared and the soundstage congested.
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 7. It is rated IP67, while the Harman Kardon Onyx Studio 7 has no water resistance. It has an adjustable EQ, which the Harman Kardon Onyx Studio 7 lacks. 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 7. It is rated higher for sound quality, and the $89.22 saving on the Zealot S78 is not enough to make up the difference.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 7 | Zealot S78 | |
|---|---|---|
| Price | $248.90 | $159.68 |
| Ranked | #14 of 98 in Boombox Size Portable Bluetooth Speakers | #97 of 98 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Aux Latency | 0ms | - |
| Bass Extension (-10dB) | 37Hz | - |
| Battery Life | 8 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| IP Rating | None | IP67 |
| Bluetooth Latency | 266ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | - |
| Party Mode | Yes (Wireless Dual Sound) | No |
| Power Input | DC Barrel Connector (19V/2.1A) | USB-C |
| Stereo | Partially (1 woofer) | Yes |
| Omnidirectional | No | No |
| TWS | No | Yes |
| Weight | 6.4 lbs (2.9 kg) | 9.7 lbs (4.4 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| App | No | No |
| EQ | No | Yes (multiple modes) |
| Power Bank | No | Yes (USB-A) |
| USB Playback | No | Yes |
| Amplifier Power | 50W RMS | 120W RMS / 150W peak |
| Dimensions | 11.3” x 11.3” (285.8 x 285.8 mm) (round design) | 16.1” x 6.6” x 7.3” (410 x 167 x 185 mm) |
| Drivers | 120mm woofer + 2x 25mm tweeters | 2x ~120mm (4.72”) woofers + 2x ~42mm tweeters + 2x passive radiators |
| Digital Aux Input | No | No |
| Bluetooth Version | 4.2 | 5.3 |
| Strap | No | Yes (detachable shoulder strap) |
| MicroSD Playback | - | Yes |
Related Speaker Comparisons
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- JBL Partybox Encore 2 vs Harman Kardon Onyx Studio 7
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- JBL Partybox Encore Essential 2 vs Harman Kardon Onyx Studio 7
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 7: $248.90 Amazon $248.90 eBay
Newer model: the Harman Kardon Onyx Studio 9, ranked lower, rated 4.1/5, released Dec 2024.
Older models: the Harman Kardon Onyx Studio 6 (ranked higher, 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: The addition of dual tweeters gives the Studio 7 a wider, more spacious presentation than older Onyx models. It delivers strong, deep bass, useful large-room volume and can pair with a second Studio 7 for stereo. Measured bass extension of 37Hz (-10dB).
Cons: Consumer Reports finds the bass prominent and boomy, mids hazy, treble slightly smeared and the soundstage congested. Battery life remains only about eight hours, it has no water rating or advanced codecs, and it is not an especially loud outdoor speaker.
Full Harman Kardon Onyx Studio 7 review and specifications →
| Released | Jan 2021 (5 years ago) |
|---|---|
| Amplifier Power | 50W RMS |
| App | No |
| Aux Input | Yes |
| Aux Latency | 0ms |
| Bass Extension (-10dB) | 37Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 266ms |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.3” x 11.3” (285.8 x 285.8 mm) (round design) |
| Drivers | 120mm woofer + 2x 25mm tweeters |
| EQ | No |
| IP Rating | None |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Wireless Dual Sound) |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2.1A) |
| Stereo | Partially (1 woofer) |
| Strap | No |
| TWS | No |
| USB Playback | No |
| Weight | 6.4 lbs (2.9 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: JBL Boombox 2 vs Onyx Studio 7 big bass battle 💋 More from alanrossreviews →
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- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers!
- KULAS TECH SHOW: Harman / Kardon Onyx Studio 5 vs Onyx Studio 7 - Close battle🔥🔥 More from KULASTECHSHOW20 →
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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