Short answer: the Yeahbox Sonic Boom Ultra. It ranks #11 of 91 boombox speakers by sound quality (rated 4.2/5) at $388 and is still sold new; the Turtlebox ranks #87 (rated 2.1/5) and is discontinued, so it is only an option used.
The Yeahbox Sonic Boom Ultra is the better-sounding choice. By far the loudest boombox tested against it, hitting 106-107dB, roughly 3-5dB louder than the JBL Boombox 4, Zealot ZE41, Tribit Stormbox Blast 2, W-King X20, and Hopestar A90/A95. It has an adjustable EQ, which the Turtlebox lacks. Watch for: 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 Turtlebox is the lighter pick. Waterproof and crushproof, loud with punchy bass. At 10 lbs (4.54 kg) it weighs much less than the Yeahbox Sonic Boom Ultra at 24.3 lbs (11 kg). Watch for: Sounds basically identical to the later Gen 2 and Gen 3: each generation mainly added features, not sound quality.
Buy the Yeahbox Sonic Boom Ultra. It is rated higher for sound quality, and the Turtlebox is discontinued, so it is only available used.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Yeahbox Sonic Boom Ultra | Turtlebox | |
|---|---|---|
| Price | $388.00 | $329 Discontinued |
| Ranked | #11 of 91 in Boombox Size Portable Bluetooth Speakers | #87 of 91 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 | 4.0 |
| Dimensions | 23.4” x 9.8” x 12.3” (595 x 248 x 313 mm) | 12” x 7” x 8.7” (305 x 178 x 222 mm) |
| Drivers | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way | 1x 6x9” (152x228mm) woofer + 1x 1” (25mm) tweeter |
| EQ | Yes (Country, Classic, and custom app EQ; custom settings don’t persist after the app closes) | No |
| Inputs | HDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic | - |
| IP Rating | IPX6 | IP67 |
| MicroSD Playback | Yes | Yes |
| Amplifier Power | 320W RMS / 500W Peak | 50W |
| Party Mode | No (TWS stereo pairing of 2 units only, no Auracast) | No |
| Power Input | USB-C (60W fast charging) | AC Power brick |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | No |
| Weight | 24.3 lbs (11 kg) | 10 lbs (4.54 kg) |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC |
| Lights | Yes | - |
| Battery Life | 24 hours (Manufacturer specified) | 25 hours (Manufacturer specified) |
| Strap | No | - |
| Bass Extension (-10dB) | - | ~65Hz |
| Power Bank | - | No |
| Built-in Microphone | - | No |
Related Speaker Comparisons
More worthwhile head-to-heads for Yeahbox Sonic Boom Ultra:
- Yeahbox Sonic Boom Ultra vs Tribit Stormbox Blast
- JBL Partybox Encore 2 vs Yeahbox Sonic Boom Ultra
- JBL PartyBox On-The-Go 2 Plus vs Yeahbox Sonic Boom Ultra
- JBL Partybox Encore Essential 2 vs Yeahbox Sonic Boom Ultra
- Yeahbox Sonic Boom Ultra vs JBL Partybox Encore
Prices on this page were last checked October 4, 2026 at 9:58 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
Yeahbox Sonic Boom Ultra: $388.00 Amazon eBay
Pros: By far the loudest boombox tested against it, hitting 106-107dB, roughly 3-5dB louder than the JBL Boombox 4, Zealot ZE41, Tribit Stormbox Blast 2, W-King X20, and Hopestar A90/A95. The massive 6x9in racetrack woofer reaches audible bass down to around 30Hz on the Country EQ preset, and a teardown confirmed genuinely robust internals: a thick vented voice coil and a dedicated crossover output per driver. HDMI ARC input/output lets it double as a TV soundbar, a feature none of its direct competitors offer.
Cons: 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 custom EQ in the app noticeably reduces bass output compared to the factory presets and doesn’t persist after the speaker powers off. No Auracast, no removable battery, a plastic handle with some flex, and heavy at 11kg (24lb) for $388. Most of the sound-quality coverage comes from enthusiast listening-test comparisons rather than independent measurement.
Full Yeahbox Sonic Boom Ultra review and specifications →
| Amplifier Power | 320W RMS / 500W Peak |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Battery Capacity | 45000mAh (Reviewer estimated) |
| Battery Life | 24 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 6.0 |
| Digital Aux Input | No |
| Dimensions | 23.4” x 9.8” x 12.3” (595 x 248 x 313 mm) |
| Drivers | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way |
| EQ | Yes (Country, Classic, and custom app EQ; custom settings don’t persist after the app closes) |
| IP Rating | IPX6 |
| Inputs | HDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic |
| Lights | Yes |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No (TWS stereo pairing of 2 units only, no Auracast) |
| Power Input | USB-C (60W fast charging) |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 24.3 lbs (11 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Jagist reviews: Yeahbox Sonic Boom Ultra Vs Zealot Ze41!!! Battle Of Big Boys!!! 😜😜😜 More from Jagistreviews →
- Jagist reviews: Yeahbox Sonic Boom Ultra Vs Zealot Ze21!!! Battle Of The Deep Bass 🥳🥳🥳
- Jagist reviews: Yeahbox Sonic Boom Ultra Vs W-king X20!!! Old Vs New!!! 🫨🫨🫨
- Techder Audios: YEAHBOX Sonic Boom Ultra VS JBL Boombox 4 "IT BEATS THE KING!?😈😱" More from techderaudios →
- Jagist reviews: Yeahbox Sonic Boom Ultra Vs Tribit Stormbox Blast 2 Firmware 11!!! Holy Crap!!! 🤩🤩🤩
- Jagist reviews: Yeahbox Sonic Boom Ultra Vs Hopestar A95!!! Battle Of Big Boys!!!! 😘😘😘
- Jagist reviews: Yeahbox Sonic Boom Ultra!!! 💥 Unboxing And Review!!! Absolutely A Beast 💯 🥵🥵🥵
- Techder Audios: YEAHBOX Sonic Boom Ultra - Soundtest "DEEP SUBWOOFER LIKE PERFORMANCE!🔥"
- Audio y Mas: El Woofer Más GRANDE en un Altavoz, Yeahbox Sonic Boom Ultra
- Jagist reviews: Yeahbox Sonic Boom Ultra Bass Test!!! What A Beast!!! 😍😍😍
- brett levesque: Yeahbox sonic boom ultra hertz test
- Jagist reviews: Yeahbox Sonic Boom Ultra Hertz Test!!! How Low Will She Go??? 😛😛😛
- Head-to-Head Comparisons
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- Yeahbox Sonic Boom Ultra vs JBL Partybox Encore Essential
- Yeahbox Sonic Boom Ultra vs Harman Kardon Onyx Studio 7
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- Yeahbox Sonic Boom Ultra vs JBL Partybox Encore
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- See all 71 comparisons
Turtlebox: $329 Discontinued eBay
Newer model: the Turtlebox Gen 3, ranked higher, rated 2.1/5.
Pros: Waterproof and crushproof, loud with punchy bass. 25 hour battery life (6 hours at full volume). Pairs with a second unit for stereo. Measured bass extension of ~65Hz (-10dB).
Cons: Sounds basically identical to the later Gen 2 and Gen 3: each generation mainly added features, not sound quality. The nearly identical Gen 3 measured a V shaped tuning, with boosted lows and highs and dipped mids, yet bass only down 10dB at about 65Hz, and only about 12W RMS from its amp; Turtlebox rated this one at just 50W. It rattles at high volume. Nowhere near its claimed 120dB at a standard one meter distance. It charges from an external AC power brick. Inside is essentially a car audio 6x9 two way speaker in a plastic box. Discontinued.
Full Turtlebox review and specifications →
| Amplifier Power | 50W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | ~65Hz |
| Battery Life | 25 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 4.0 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 12” x 7” x 8.7” (305 x 178 x 222 mm) |
| Drivers | 1x 6x9” (152x228mm) woofer + 1x 1” (25mm) tweeter |
| EQ | No |
| IP Rating | IP67 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | No |
| Power Input | AC Power brick |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | No |
| Weight | 10 lbs (4.54 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons