Short answer: the Yeahbox Sonic Boom Ultra. It ranks #11 of 112 boombox speakers by sound quality (rated 4.2/5) at $388 and is still sold new; the Harman Kardon Onyx Studio 5 ranks #24 (rated 3.9/5) and is discontinued, so it is only an option used. The Harman Kardon Onyx Studio 5’s replacement, the Harman Kardon Onyx Studio 9, is rated 4.1/5 at $184.99.
The Yeahbox Sonic Boom Ultra is the better-sounding, longer-running choice. A massively loud boombox with deep bass, long battery life, and HDMI ARC so it can double as a TV soundbar. It is rated for 24 hours of battery against 8 for the Harman Kardon Onyx Studio 5. It has an adjustable EQ, which the Harman Kardon Onyx Studio 5 lacks. 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 Harman Kardon Onyx Studio 5 is the lighter choice. An iconic round speaker with warm, relaxed sound and generous bass for casual indoor listening. At 6.6 lbs (3 kg) it weighs much less than the Yeahbox Sonic Boom Ultra at 24.3 lbs (11 kg). It links with other speakers (Wireless Dual Sound), which the Yeahbox Sonic Boom Ultra cannot. The tradeoff: The large bass boost can mask lower-mid detail and make dense mixes muddy.
Buy the Yeahbox Sonic Boom Ultra. It is rated higher for sound quality, and the Harman Kardon Onyx Studio 5 is discontinued, so it is only available used.
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.
An iconic round speaker with warm, relaxed sound and generous bass for casual indoor listening.
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 | Harman Kardon Onyx Studio 5 | |
|---|---|---|
| Price | $388.00 | $499.99 Discontinued |
| Ranked | #11 of 112 in Boombox Size Portable Bluetooth Speakers | #24 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 | 4.2 |
| 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) |
| Drivers | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way | 120mm woofer + 25mm tweeter + 2x passive radiators |
| 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 | IPX7 |
| MicroSD Playback | Yes | - |
| Amplifier Power | 320W RMS / 500W Peak | 50W |
| 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 | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) |
| USB Playback | Yes | No |
| Weight | 24.3 lbs (11 kg) | 6.6 lbs (3 kg) |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC |
| Lights | Yes | - |
| Battery Life | 24 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| Strap | No | No |
| Power Bank | - | No |
| Built-in Microphone | - | Yes |
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