Short answer: the Harman Kardon Onyx Studio 6. It ranks #11 of 73 boombox speakers by sound quality at $130; the Zealot ZE21 ranks #15 and costs $187.15, so there is not much of a tradeoff to weigh.
The case for the Harman Kardon Onyx Studio 6: Warm sound with boosted bass. The tradeoff: 8 hour battery at medium volume.
What the Zealot ZE21 gets right: Great value for the bass performance, play time and max volume in the boombox class, though the Zealot ZE41 now beats it out. The catch: A little rolled off up top and not that balanced through the rest of the range.
Buy the Harman Kardon Onyx Studio 6. It ranks higher for sound quality than the Zealot ZE21 and costs less, so there is no real case for the other one.
If battery life is a priority, the Zealot ZE21 is rated for 40 hours versus 8 hours for the Harman Kardon Onyx Studio 6.
Specifications Side By Side
| Harman Kardon Onyx Studio 6 | Zealot ZE21 | |
|---|---|---|
| Price | $130 | $187.15 |
| Ranked | #11 of 73 in Boombox Size Portable Bluetooth Speakers | #15 of 73 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | 37Hz | 36Hz |
| Battery Life | 8 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Built in Microphone | Yes | No |
| IP Rating | IPX7 | IPX6 |
| Bluetooth Latency | 180ms | - |
| Max Volume | 96dB | 116dB |
| Party Mode | Yes (Wireless Dual Sound) | Yes (PartyAdd up to 100 speakers) |
| Power Input | DC Barrel Connector (19V/2A) | USB-C |
| Stereo | Yes | 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 | 6.5 lbs / 2.94 kg | 20.4 lbs / 9.27 kg |
| Bluetooth Codecs | SBC | SBC |
| App | No | No |
| EQ | No | Yes (multiple modes) |
| Power Bank | No | Yes (USB-A + USB-C) |
| USB Playback | No | Yes |
| Bluetooth Version | 4.2 | - |
| Output Power | 50W RMS | 250W |
| Dimensions | 5" x 11.5" x 11.2" (128 x 291 x 284 mm) | 16.7" x 10.3" x 14.3" (424 x 262 x 363 mm) |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters | 130W subwoofer + 2x 50mm woofers + passive radiators |
| Digital Aux Input | No | No |
| MicroSD Playback | - | Yes |
Related Speaker Comparisons
More useful head-to-heads from the same speaker class:
- Zealot S89 vs Zealot ZE01
- Harman Kardon Onyx Studio 8 vs Harman Kardon Onyx Studio 9
- Earfun Uboom X vs Zealot ZE41
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 6 vs Zealot S89
The Two Speakers In Full
Harman Kardon Onyx Studio 6: $130 Amazon
Pros: Warm sound with boosted bass. Oluv liked it slightly better than the newer Onyx 7.
Cons: 8 hour battery at medium volume. Not at loud as others.
Full Harman Kardon Onyx Studio 6 review and specifications →
| App | No |
|---|---|
| Aux Input | Yes |
| Bass Extension (-10dB) | 37Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 180ms |
| Bluetooth Version | 4.2 |
| Built in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 5" x 11.5" x 11.2" (128 x 291 x 284 mm) |
| Drivers | 2x 75mm woofers + 2x 20mm tweeters |
| EQ | No |
| IP Rating | IPX7 |
| Max Volume | 96dB |
| Omnidirectional | No |
| Output Power | 50W RMS |
| Party Mode | Yes (Wireless Dual Sound) |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2A) |
| Stereo | Yes |
| 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 | 6.5 lbs / 2.94 kg |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Onyx Studio 7 vs Onyx Studio 6 - massive deep bass battle 😁
- That Speaker Guy: Harman Kardon Onyx Studio 6 vs Devialet Mania
- Ezekielo: Citation 200 vs Onyx Studio 6 vs Bose Portable Speaker Sound Comparison
- Alan Ross Reviews: Harman Kardon Go+ Play 2 mini or Onyx Studio 6 - best speaker for bass?
- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers!
- Reddit Search for Harman Kardon Onyx Studio 6 Review
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 8
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 7
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 6 vs Vifa Copenhagen 2.0
- Harman Kardon Onyx Studio 6 vs Zealot ZE41
- Harman Kardon Onyx Studio 6 vs JBL Partybox Encore Essential
- Harman Kardon Onyx Studio 6 vs JBL Partybox Encore
- Harman Kardon Onyx Studio 6 vs Zealot S89
- See all 18 comparisons
Zealot ZE21: $187.15 Aliexpress Amazon
Pros: Great value for the bass performance, play time and max volume in the boombox class, though the Zealot ZE41 now beats it out.
Cons: A little rolled off up top and not that balanced through the rest of the range. Clarity isn’t as good as better speakers. Bass EQ is bloated and muddy sounding
Full Zealot ZE21 review and specifications →
| App | No |
|---|---|
| Aux Input | Yes |
| Bass Extension (-10dB) | 36Hz |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Built in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.7" x 10.3" x 14.3" (424 x 262 x 363 mm) |
| Drivers | 130W subwoofer + 2x 50mm woofers + passive radiators |
| EQ | Yes (multiple modes) |
| IP Rating | IPX6 |
| Max Volume | 116dB |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Output Power | 250W |
| Party Mode | Yes (PartyAdd up to 100 speakers) |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 20.4 lbs / 9.27 kg |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Jagist reviews: Jbl Boombox 4 Vs Zealot Ze21!!!
- Jagist reviews: Zealot Ze21 Vs Tribit Stormbox Blast 2!!!
- Techder Audios: JBL Boombox 4 VS Zealot ZE21 BATTLE OF THE BOOMBOXES!
- Jay’s Straight Up Reviews & More: Zealot ZE21 vs JBL Boombox 3 Tailgater Special @20ft. The Budget Beast Against the OG Boombox
- Reddit Search for Zealot ZE21 Review
- Head-to-Head Comparisons
- Zealot ZE21 vs Zealot ZE41
- Zealot ZE21 vs Zealot S89
- Zealot ZE21 vs JBL Boombox 4
- Zealot ZE21 vs Harman Kardon Onyx Studio 9
- Zealot ZE21 vs Harman Kardon Onyx Studio 7
- Zealot ZE21 vs Harman Kardon Go + Play 2
- Zealot ZE21 vs Harman Kardon Onyx Studio 5
- Zealot ZE21 vs Harman Kardon Onyx Studio 8
- See all 19 comparisons