Short answer: the Harman Kardon Onyx Studio 9, if you are buying new. The Harman Kardon Onyx Studio 5 ranks higher than the Zealot S78 (#24 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 5 is the better-sounding, lighter option. The iconic circular cabinet and integrated handle make it an attractive room-to-room speaker. At 6.6 lbs (3 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 tradeoff: The large bass boost can mask lower-mid detail and make dense mixes muddy.
The Zealot S78 is the longer-running pick. 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 5. It has an adjustable EQ, which the Harman Kardon Onyx Studio 5 lacks. The catch: 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 5; it is rated higher for sound quality than the Zealot S78.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 5 | Zealot S78 | |
|---|---|---|
| Price | $499.99 Discontinued | $159.68 |
| Ranked | #24 of 98 in Boombox Size Portable Bluetooth Speakers | #97 of 98 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Battery Life | 8 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| IP Rating | IPX7 | IP67 |
| 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 | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) | Yes |
| Weight | 6.6 lbs (3 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 |
| Built-in Microphone | Yes | No |
| Amplifier Power | 50W | 120W RMS / 150W peak |
| Dimensions | 11.3” x 11.3” (285.8 x 285.8 mm) | 16.1” x 6.6” x 7.3” (410 x 167 x 185 mm) |
| Drivers | 120mm woofer + 25mm tweeter + 2x passive radiators | 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
How Harman Kardon Onyx Studio 5 compares with other leading options:
- Tribit Stormbox Blast vs Harman Kardon Onyx Studio 5
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 5
- JBL Partybox Encore 2 vs Harman Kardon Onyx Studio 5
- JBL PartyBox On-The-Go 2 Plus vs Harman Kardon Onyx Studio 5
- JBL Partybox Encore Essential 2 vs Harman Kardon Onyx Studio 5
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 5: $499.99 Discontinued Amazon $499.99 eBay
Newer model: the Harman Kardon Onyx Studio 9, ranked higher, rated 4.1/5, released Dec 2024.
Older model: the Harman Kardon Onyx Studio 4 (rated 3.3/5). See every Harman Kardon Onyx Studio generation.
Pros: The iconic circular cabinet and integrated handle make it an attractive room-to-room speaker. Reviews praise its generous bass, balanced mids and smooth top end at moderate levels, giving it a warm, relaxed presentation for casual indoor music.
Cons: The large bass boost can mask lower-mid detail and make dense mixes muddy. Battery life is only around eight hours at moderate volume, it is not especially loud, and it has no water resistance for outdoor use. Discontinued.
Full Harman Kardon Onyx Studio 5 review and specifications →
| Released | Sep 2018 (8 years ago) |
|---|---|
| Amplifier Power | 50W |
| App | No |
| Aux Input | Yes |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.3” x 11.3” (285.8 x 285.8 mm) |
| Drivers | 120mm woofer + 25mm tweeter + 2x passive radiators |
| EQ | No |
| IP Rating | IPX7 |
| 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 | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) |
| USB Playback | No |
| Weight | 6.6 lbs (3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers! More from alanrossreviews →
- KULAS TECH SHOW: Harman / Kardon Onyx Studio 5 vs Onyx Studio 7 - Close battle🔥🔥 More from KULASTECHSHOW20 →
- OCM Reviews: Onyx Studio 4 Vs Onyx Studio 5 - Sound Quality Comparison - Bluetooth Speaker
- Head-to-Head Comparisons
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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