Short answer: the Harman Kardon Onyx Studio 7 if sound quality matters most, the Zealot S78 if price matters most. The Harman Kardon Onyx Studio 7 ranks #12 of 73 boombox speakers at $298.90. The Zealot S78 ranks #73 at $159.68, $139.22 cheaper.
What the Harman Kardon Onyx Studio 7 offers: Warm sound with boosted bass. Watch for: Sounds a little sterile. 8 hour battery at medium volume, teeny bit less bass than the Onyx 6. Not at loud as others. No water rating.
What the Zealot S78 offers: 120W RMS output with 150W peak power, exceptional 40-hour battery life, power bank function, IP67 waterproof, EQ with multiple modes, dual woofers with tweeters and passive radiators, MicroSD and USB playback, AUX input, TWS stereo pairing, USB-C charging Watch for: Gets distorted above 50%. Not much bass. Volume level fluctuates at high volume.
Buy the Harman Kardon Onyx Studio 7 when sound quality outweighs the price for you, and the Zealot S78 when the price outweighs sound quality instead.
If sound quality matters at all to you, skip the Zealot S78. It ranks near the bottom of the 73 boombox speakers, so look higher up the list instead.
Battery life favors the Zealot S78: rated for 40 hours against 8 hours for the Harman Kardon Onyx Studio 7.
There is a real gap in water resistance: the Zealot S78 at IP67 (brief submersion) against the Harman Kardon Onyx Studio 7, which has no water resistance.
Specifications Side By Side
| Harman Kardon Onyx Studio 7 | Zealot S78 | |
|---|---|---|
| Price | $298.90 | $159.68 |
| Ranked | #12 of 73 in Boombox Size Portable Bluetooth Speakers | #73 of 73 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 | - |
| Max Volume | 96dB | - |
| 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 Codecs | SBC | SBC |
| App | No | No |
| EQ | No | Yes (multiple modes) |
| Power Bank | No | Yes (USB-A) |
| USB Playback | No | Yes |
| Output 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 | 2x 75mm woofers + 2x 20mm tweeters | 2x ~120mm (4.72") woofers + 2x ~42mm tweeters + 2x passive radiators |
| Digital Aux Input | No | No |
| MicroSD Playback | - | Yes |
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Prices on this page were last checked August 27, 2026 at 10:09 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: $298.90 Amazon eBay
Pros: Warm sound with boosted bass.
Cons: Sounds a little sterile. 8 hour battery at medium volume, teeny bit less bass than the Onyx 6. Not at loud as others. No water rating.
Full Harman Kardon Onyx Studio 7 review and specifications →
| App | No |
|---|---|
| Aux Input | Yes |
| Aux Latency | 0ms |
| Bass Extension (-10dB) | 37Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 266ms |
| Built in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.3" x 11.3" (285.8 x 285.8 mm) (round design) |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters |
| EQ | No |
| IP Rating | None |
| Max Volume | 96dB |
| Omnidirectional | No |
| Output Power | 50W RMS |
| Party Mode | Yes (Wireless Dual Sound) |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2.1A) |
| Stereo | Partially (1 woofer) |
| 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 →
- Alan Ross Reviews: Onyx Studio 7 vs Onyx Studio 6 - massive deep bass battle 😁
- Geri’s Collection: Harman Kardon Onyx 7 vs Onyx 4
- KULAS TECH SHOW: Harman / Kardon Onyx Studio 5 vs Onyx Studio 7 - Close battle🔥🔥 More from KULASTECHSHOW20 →
- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers!
- Reddit Search for Harman Kardon Onyx Studio 7 Review
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 7 vs Harman Kardon Onyx Studio 6
- Harman Kardon Onyx Studio 7 vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 7 vs Harman Kardon Onyx Studio 8
- Harman Kardon Onyx Studio 7 vs Zealot ZE41
- Harman Kardon Onyx Studio 7 vs Zealot ZE21
- Harman Kardon Onyx Studio 7 vs Zealot S89
- Harman Kardon Onyx Studio 7 vs JBL Partybox Encore Essential
- Harman Kardon Onyx Studio 7 vs JBL Boombox 4
- See all 44 comparisons
Zealot S78: $159.68 Amazon Aliexpress eBay
Pros: 120W RMS output with 150W peak power, exceptional 40-hour battery life, power bank function, IP67 waterproof, EQ with multiple modes, dual woofers with tweeters and passive radiators, MicroSD and USB playback, AUX input, TWS stereo pairing, USB-C charging
Cons: Gets distorted above 50%. Not much bass. Volume level fluctuates at high volume.
Full Zealot S78 review and specifications →
| App | No |
|---|---|
| Aux Input | Yes |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| 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 |
| Output Power | 120W RMS / 150W peak |
| Party Mode | No |
| Power Bank | Yes (USB-A) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 9.7 lbs / 4.4 kg |
- Reviews, Comparisons and Sound Samples
- Jay’s Straight Up Reviews & More: W-King X20 vs Zealot S78 Bluetooth Boombox Battle Outdoor Tailgater Special 🚗 Let the Whoopin’ Begin More from JaysStraightUpReviews →
- Jay’s Straight Up Reviews & More: DBSOARS F29 Max vs Zealot S78 🛜 (5B) Budget Bluetooth Boombox Basement Battle 🔊 Bass Modes Enabled
- Reddit Search for Zealot S78 Review
- Head-to-Head Comparisons