Short answer: the Yeahbox Sonic Boom Ultra for better sound quality, the Zealot S89 for the lower price. The Yeahbox Sonic Boom Ultra ranks #11 of 112 boombox speakers, rated 4.2/5, at $388. The Zealot S89 ranks #19, rated 4.0/5, at $193.58, $194.42 cheaper.
Why pick the Yeahbox Sonic Boom Ultra: A massively loud boombox with deep bass, long battery life, and HDMI ARC so it can double as a TV soundbar. The tradeoff: The 500W peak-power rating doesn’t fully hold up: it gets noisy above roughly 80-90% volume, and the midrange isn’t fully refined, sometimes sitting a touch too forward.
The Zealot S89 is the longer-running, lighter option. A great value boombox with deep bass, very high volume, a 40 hour battery and water resistance for outdoor parties. It is rated for 40 hours of battery against 24 for the Yeahbox Sonic Boom Ultra. At 16.1 lbs (7.3 kg) it weighs noticeably less than the Yeahbox Sonic Boom Ultra at 24.3 lbs (11 kg). It links with other speakers (PartyAdd up to 100 speakers), which the Yeahbox Sonic Boom Ultra cannot. The tradeoff: At high volume, listener reports describe the bass as loose or muddy and the overall balance as less clear than better boombox speakers.
Buy the Yeahbox Sonic Boom Ultra when sound quality outweighs the price for you, and the Zealot S89 when the price outweighs sound quality instead.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
A massively loud boombox with deep bass, long battery life, and HDMI ARC so it can double as a TV soundbar.
A great value boombox with deep bass, very high volume, a 40 hour battery and water resistance for outdoor parties.
Prices on this page were last checked October 31, 2026 at 7:11 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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Specifications Side By Side
| Yeahbox Sonic Boom Ultra | Zealot S89 | |
|---|---|---|
| Price | $388.00 | $193.58 |
| Ranked | #11 of 112 in Boombox Size Portable Bluetooth Speakers | #19 of 112 in Boombox Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | Yes | Yes |
| Battery Capacity | 45000mAh (Reviewer estimated) | - |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 6.0 | 5.3 |
| Dimensions | 23.4” x 9.8” x 12.3” (595 x 248 x 313 mm) | 21.2” x 10.4” x 9.4” (538 x 265 x 240 mm) |
| Drivers | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way | 130W subwoofer + 2x 40mm drivers + 2x tweeters |
| EQ | Yes (Country, Classic, and custom app EQ; custom settings don’t persist after the app closes) | Yes (multiple modes) |
| Inputs | HDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic | - |
| IP Rating | IPX6 | IPX6 |
| MicroSD Playback | Yes | Yes |
| Amplifier Power | 320W RMS / 500W Peak | 250W |
| Party Mode | No (TWS stereo pairing of 2 units only, no Auracast) | Yes (PartyAdd up to 100 speakers) |
| Power Input | USB-C (60W fast charging) | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | Yes |
| Weight | 24.3 lbs (11 kg) | 16.1 lbs (7.3 kg) |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC |
| Lights | Yes | - |
| Battery Life | 24 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Strap | No | No |
| Bass Extension (-10dB) | - | 36Hz |
| Power Bank | - | Yes (USB-A + USB-C) |
| Built-in Microphone | - | No |
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