Short answer: the Yeahbox Sonic Boom Ultra on measured sound quality, the Harman Kardon Onyx Studio 7 on price. The Yeahbox Sonic Boom Ultra ranks #10 of 75 boombox speakers at $349.20. The Harman Kardon Onyx Studio 7 ranks #13 at $248.90, $100.30 cheaper.
What the Yeahbox Sonic Boom Ultra offers: 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. 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 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.
What the Harman Kardon Onyx Studio 7 offers: The addition of dual tweeters gives the Studio 7 a wider, more spacious presentation than older Onyx models. It delivers strong, deep bass, useful large-room volume and can pair with a second Studio 7 for stereo. Watch for: Consumer Reports finds the bass prominent and boomy, mids hazy, treble slightly smeared and the soundstage congested. Battery life remains only about eight hours, it has no water rating or advanced codecs, and it is not an especially loud outdoor speaker.
Buy the Yeahbox Sonic Boom Ultra when sound quality outweighs the price for you, and the Harman Kardon Onyx Studio 7 when the price outweighs sound quality instead.
There is a real gap in water resistance: the Yeahbox Sonic Boom Ultra at IPX6 (powerful water jets) against the Harman Kardon Onyx Studio 7, which has no water resistance.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Yeahbox Sonic Boom Ultra | Harman Kardon Onyx Studio 7 | |
|---|---|---|
| Price | $349.20 | $248.90 |
| Ranked | #10 of 75 in Boombox Size Portable Bluetooth Speakers | #13 of 75 in Boombox Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | Yes | Yes |
| Battery Capacity | 45000mAh (Reviewer estimated) | - |
| Bluetooth Version | 6.0 | - |
| Dimensions | 23.4" x 9.8" x 12.3" (595 x 248 x 313 mm) | 11.3" x 11.3" (285.8 x 285.8 mm) (round design) |
| Drivers | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way | 2x 75mm woofers + 2x 20mm tweeters |
| 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 | None |
| MicroSD Playback | Yes | - |
| Amplifier Power | 320W RMS / 500W Peak | 50W RMS |
| Party Mode | No (TWS stereo pairing of 2 units only, no Auracast) | Yes (Wireless Dual Sound) |
| Power Input | USB-C (60W fast charging) | DC Barrel Connector (19V/2.1A) |
| Stereo | Yes | Partially (1 woofer) |
| Omnidirectional | No | No |
| TWS | Yes | No |
| USB Playback | Yes | No |
| Weight | 24.3 lbs (11 kg) | 6.4 lbs (2.9 kg) |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC |
| Lights | Yes | - |
| Aux Latency | - | 0ms |
| Bass Extension (-10dB) | - | 37Hz |
| Battery Life | - | 8 hours (Manufacturer specified) |
| Built-in Microphone | - | Yes |
| Bluetooth Latency | - | 266ms |
| Maximum SPL | - | 96dB (measured by Alan Ross Reviews) |
| Power Bank | - | 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 Encore Essential 2 vs Yeahbox Sonic Boom Ultra
- Yeahbox Sonic Boom Ultra vs JBL Partybox Encore
- JBL Partybox Encore Essential vs Yeahbox Sonic Boom Ultra
Prices on this page were last checked September 16, 2026 at 12:41 AM 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: $349.20 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) |
| 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 |
| 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 2
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- See all 44 comparisons
Harman Kardon Onyx Studio 7: $248.90 Amazon eBay
Pros: The addition of dual tweeters gives the Studio 7 a wider, more spacious presentation than older Onyx models. It delivers strong, deep bass, useful large-room volume and can pair with a second Studio 7 for stereo. Measured bass extension of 37Hz (-10dB).
Cons: Consumer Reports finds the bass prominent and boomy, mids hazy, treble slightly smeared and the soundstage congested. Battery life remains only about eight hours, it has no water rating or advanced codecs, and it is not an especially loud outdoor speaker.
Full Harman Kardon Onyx Studio 7 review and specifications →
| Amplifier Power | 50W RMS |
|---|---|
| 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 |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| 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!
- Head-to-Head Comparisons
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- 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 ZE51
- 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
- See all 55 comparisons


