Short answer: the Zealot S89, on value and output. It delivers great bass performance, play time and max volume for the boombox class but is on the heavy side. The Harman Kardon Onyx Studio 5 counters with an elegant circular design and carrying handle, yet it shares the warm, boosted-bass sound and costs $499.99 against $259.99.
Buy the Zealot S89. It is rated higher for sound quality; the Harman Kardon Onyx Studio 5 is no longer sold new.
If battery life is a priority, the Zealot S89 is rated for 40 hours versus 8 hours for the Harman Kardon Onyx Studio 5.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Zealot S89 | Harman Kardon Onyx Studio 5 | |
|---|---|---|
| Price | $259.99 | $499.99 Discontinued |
| Ranked | #19 of 90 in Boombox Size Portable Bluetooth Speakers | #24 of 90 in Boombox Size Portable Bluetooth Speakers |
| App | No | No |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | 36Hz | - |
| Battery Life | 40 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| EQ | Yes (multiple modes) | No |
| IP Rating | IPX6 | IPX7 |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| MicroSD Playback | Yes | - |
| Party Mode | Yes (PartyAdd up to 100 speakers) | Yes (Wireless Dual Sound) |
| Power Input | USB-C | DC Barrel Connector (19V/2.1A) |
| Stereo | Yes | Partially (1 woofer) |
| Omnidirectional | No | No |
| TWS | Yes | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) |
| Weight | 16.1 lbs (7.3 kg) | 6.6 lbs (3 kg) |
| Power Bank | Yes (USB-A + USB-C) | No |
| USB Playback | Yes | No |
| Built-in Microphone | No | Yes |
| Amplifier Power | 250W | 50W |
| Dimensions | 21.2” x 10.4” x 9.4” (538 x 265 x 240 mm) | 11.3” x 11.3” (285.8 x 285.8 mm) |
| Drivers | 130W subwoofer + 2x 40mm drivers + 2x tweeters | 120mm woofer + 25mm tweeter + 2x passive radiators |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.3 | 4.2 |
| Strap | No | No |
Related Speaker Comparisons
More top alternatives to Zealot S89:
- Tribit Stormbox Blast vs Zealot S89
- Harman Kardon Go + Play 3 vs Zealot S89
- JBL Partybox Encore 2 vs Zealot S89
- JBL PartyBox On-The-Go 2 Plus vs Zealot S89
- JBL Partybox Encore Essential 2 vs Zealot S89
Prices on this page were last checked October 2, 2026 at 10:18 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
Zealot S89: $259.99 Amazon AliExpress eBay
Pros: A 7.3kg boombox with a claimed 36Hz bass extension, 40-hour battery life, IPX6 protection, USB-C charging, aux, USB and microSD playback, TWS and multi-speaker PartyAdd. Listener comparisons find it capable of very high output and substantial bass for outdoor use. A great value for its bass, battery life and maximum volume. Measured bass extension of 36Hz (-10dB).
Cons: At high volume, listener reports describe the bass as loose or muddy and the overall balance as less clear than better boombox speakers. The heavy cabinet and basic finish also make it less polished for daily portability, while its multiple EQ modes cannot substitute for a genuinely neutral tuning.
Full Zealot S89 review and specifications →
| Amplifier Power | 250W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 36Hz |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 21.2” x 10.4” x 9.4” (538 x 265 x 240 mm) |
| Drivers | 130W subwoofer + 2x 40mm drivers + 2x tweeters |
| EQ | Yes (multiple modes) |
| IP Rating | IPX6 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | Yes (PartyAdd up to 100 speakers) |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 16.1 lbs (7.3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Oluv Patreon: Zealot S89 vs Yeahbox Boom Max3 - indoor listening test More from Oluv’Sone →
- Oluv Patreon: Zealot S89 vs Yeahbox Sonic Boom Max3 - outdoor test
- Dominik Reviews: Zealot S89 vs JBL Boombox 4 - JBL Alternative? Sound Test More from Dominik Reviews →
- Jagist reviews: Jbl Boombox 4 Vs Zealot S89!!! More from Jagistreviews →
- Techder Audios: ZEALOT S89 VS ZEALOT ZE01 EXTREME POWERFULL VS COMPACTER BASS PERFORMANCE! More from techderaudios →
- Head-to-Head Comparisons
Harman Kardon Onyx Studio 5: $499.99 Discontinued Amazon eBay
Newer model: the Harman Kardon Onyx Studio 9, ranked higher, rated 4.1/5.
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 →
| 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
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 5 vs Harman Kardon Go + Play 2
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- Harman Kardon Onyx Studio 5 vs JBL Boombox 3
- Harman Kardon Onyx Studio 5 vs JBL Boombox 4
- Harman Kardon Onyx Studio 5 vs Zealot ZE21
- Harman Kardon Onyx Studio 5 vs Tribit Stormbox Blast 2
- Harman Kardon Onyx Studio 5 vs Zealot ZE41
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- See all 58 comparisons