Short answer: the Yeahbox Sonic Boom Ultra. It ranks #11 of 112 boombox speakers by sound quality, rated 4.2/5, at $388. The JBL Authentics 300 ranks #46, rated 3.5/5, at $299.95, $88.05 cheaper, not enough of a saving to outweigh the sound-quality gap.
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 JBL Authentics 300. It is rated IPX6, while the JBL Authentics 300 has no water resistance. It keeps a wired aux input, which the JBL Authentics 300 lacks. The catch: 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 JBL Authentics 300 is the lighter pick. A retro styled smart speaker with both Alexa and Google Assistant, a leather handle and battery power. At 10.8 lbs (4.9 kg) it weighs much less than the Yeahbox Sonic Boom Ultra at 24.3 lbs (11 kg). It links with other speakers (Wi-Fi Multi-Room), which the Yeahbox Sonic Boom Ultra cannot. Watch for: Narrow sounding, bass not as deep as others.
Buy the Yeahbox Sonic Boom Ultra. It is rated higher for sound quality, and the $88.05 you would save on the JBL Authentics 300 does not close the gap.
Want more options? Browse the full Portable Bluetooth rankings.
A massively loud boombox with deep bass, long battery life, and HDMI ARC so it can double as a TV soundbar.
A retro styled smart speaker with both Alexa and Google Assistant, a leather handle and battery power.
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Specifications Side By Side
| Yeahbox Sonic Boom Ultra | JBL Authentics 300 | |
|---|---|---|
| Price | $388.00 | $299.95 |
| Ranked | #11 of 112 in Boombox Size Portable Bluetooth Speakers | #46 of 112 in Boombox Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Aux Input | Yes | No |
| 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) | 13.5” x 7.7” x 7.1” (342 x 195.6 x 180.3 mm) |
| Drivers | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way | 1” tweeter + 4” woofer + passive radiators |
| EQ | Yes (Country, Classic, and custom app EQ; custom settings don’t persist after the app closes) | Yes (App EQ) |
| 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 | No |
| Amplifier Power | 320W RMS / 500W Peak | 100W |
| Party Mode | No (TWS stereo pairing of 2 units only, no Auracast) | Yes (Wi-Fi Multi-Room) |
| Power Input | USB-C (60W fast charging) | AC Power cable |
| Stereo | Yes | Partially (1 woofer) |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | Yes |
| Weight | 24.3 lbs (11 kg) | 10.8 lbs (4.9 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 |
| Bass Extension (-10dB) | - | 45Hz |
| Maximum SPL | - | 100dB (measured by Alan Ross Reviews) |
| Wi-Fi | - | Yes |
| Power Bank | - | No |
| Built-in Microphone | - | Yes |
| Voice Assistants | - | Amazon Alexa & Google Assistant (simultaneous) |
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