Short answer: the JBL Partybox Encore 2. It ranks #4 of 112 boombox speakers by sound quality, rated 4.4/5, at $330; the Yeahbox Sonic Boom Ultra ranks #11, rated 4.2/5, and costs $388, which makes this an easy call rather than a real tradeoff.
The JBL Partybox Encore 2 is the lighter choice. A compact karaoke party speaker with two wireless mics, better balanced sound than the original and a long battery. At 14.1 lbs (6.4 kg) it weighs much less than the Yeahbox Sonic Boom Ultra at 24.3 lbs (11 kg). It links with other speakers (Auracast), which the Yeahbox Sonic Boom Ultra cannot. The catch: It still lacks some upper-bass punch and cannot match the scale of the larger PartyBoxes.
The Yeahbox Sonic Boom Ultra is the longer-running, tougher 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 15 for the JBL Partybox Encore 2. It is rated IPX6 against IPX4 for the JBL Partybox Encore 2. 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.
Buy the JBL Partybox Encore 2. It is rated higher for sound quality than the Yeahbox Sonic Boom Ultra and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Looking for alternatives? See the complete Portable Bluetooth rankings.
A compact karaoke party speaker with two wireless mics, better balanced sound than the original and a long battery.
A massively loud boombox with deep bass, long battery life, and HDMI ARC so it can double as a TV soundbar.
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Specifications Side By Side
| JBL Partybox Encore 2 | Yeahbox Sonic Boom Ultra | |
|---|---|---|
| Price | $330 | $388.00 |
| Ranked | #4 of 112 in Boombox Size Portable Bluetooth Speakers | #11 of 112 in Boombox Size Portable Bluetooth Speakers |
| App | Yes (JBL PartyBox app) | Yes |
| Aux Input | Yes | Yes |
| Battery Life | 15 hours (Manufacturer specified) | 24 hours (Manufacturer specified) |
| Built-in Microphone | No | - |
| EQ | Yes (7 band App EQ) | Yes (Country, Classic, and custom app EQ; custom settings don’t persist after the app closes) |
| IP Rating | IPX4 | IPX6 |
| Maximum SPL | 110dB (measured by Alan Ross Reviews) | - |
| Party Mode | Yes (Auracast) | No (TWS stereo pairing of 2 units only, no Auracast) |
| Power Bank | Yes (USB-C) | - |
| Power Input | AC Power cord | USB-C (60W fast charging) |
| Removable Battery | Yes | - |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | Yes |
| Weight | 14.1 lbs (6.4 kg) | 24.3 lbs (11 kg) |
| Wireless Microphones | Yes 2 Included | - |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.4 | 6.0 |
| Amplifier Power | 100W RMS | 320W RMS / 500W Peak |
| Dimensions | 12.6” x 13.3” x 10.4” (319.5 x 338.6 x 263 mm) | 23.4” x 9.8” x 12.3” (595 x 248 x 313 mm) |
| Drivers | 1x 135mm (5.25”) woofer + 2x 20mm (0.75”) dome tweeters | 6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way |
| Digital Aux Input | No | No |
| Lights | Yes | Yes |
| Strap | No | No |
| Bass Extension (-10dB) | 42Hz | - |
| Battery Capacity | - | 45000mAh (Reviewer estimated) |
| Inputs | - | HDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic |
| MicroSD Playback | - | Yes |
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