JBL Partybox Encore 2 vs Yeahbox Sonic Boom Ultra

Last updated: September 16, 2026

Short answer: the JBL Partybox Encore 2. It ranks #4 of 75 boombox speakers by sound quality at $330; the Yeahbox Sonic Boom Ultra ranks #10 and costs $349.20, which makes this an easy call rather than a real tradeoff.

JBL Partybox Encore 2 vs Yeahbox Sonic Boom Ultra

What the JBL Partybox Encore 2 offers: The Encore 2 improves the original with dome tweeters, a less boomy balance, slightly deeper bass, longer battery life and two included wireless microphones. Its compact karaoke-ready design and 7-band EQ make it more adaptable indoors than the earlier Encore. Watch for: It still lacks some upper-bass punch and cannot match the scale of the larger PartyBoxes. The main value is compact karaoke convenience rather than full-range party output.

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.

Buy the JBL Partybox Encore 2. It ranks higher for sound quality than the Yeahbox Sonic Boom Ultra and costs less, so there is no real case for the other one.

Looking for alternatives? See the complete Portable Bluetooth rankings.

Buy the JBL Partybox Encore 2 at Samsclub →Buy the Yeahbox Sonic Boom Ultra at Amazon ($349.20) →

Specifications Side By Side

JBL Partybox Encore 2 Yeahbox Sonic Boom Ultra
Price$330$349.20
Ranked#4 of 75 in Boombox Size Portable Bluetooth Speakers#10 of 75 in Boombox Size Portable Bluetooth Speakers
AppYes (JBL PartyBox app)Yes
Aux InputYesYes
Battery Life15 hours (Manufacturer specified)-
Built-in MicrophoneNo-
EQYes (7 band App EQ)Yes (Country, Classic, and custom app EQ; custom settings don't persist after the app closes)
IP RatingIPX4IPX6
Maximum SPL110dB (measured by Alan Ross Reviews)-
Party ModeYes (Auracast)No (TWS stereo pairing of 2 units only, no Auracast)
Power BankYes (USB-C)-
Power InputAC Power cordUSB-C (60W fast charging)
Removable BatteryYes-
StereoYesYes
OmnidirectionalNoNo
TWSYesYes
USB PlaybackYesYes
Weight14.1 lbs (6.4 kg)24.3 lbs (11 kg)
Wireless MicrophonesYes 2 Included-
Bluetooth CodecsSBCSBC (inferred; additional codecs unverified)
Bluetooth Version5.46.0
Amplifier Power100W RMS320W RMS / 500W Peak
Dimensions12.6" 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)
Drivers1x 135mm (5.25") woofer + 2x 20mm (0.75") dome tweeters6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way
Digital Aux InputNoNo
LightsYesYes
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
Buy the JBL Partybox Encore 2 at Samsclub →Buy the Yeahbox Sonic Boom Ultra at Amazon ($349.20) →

More top alternatives to JBL Partybox Encore 2:

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

JBL Partybox Encore 2: $330 Samsclub eBay

JBL Partybox Encore 2 ranking card

Pros: The Encore 2 improves the original with dome tweeters, a less boomy balance, slightly deeper bass, longer battery life and two included wireless microphones. Its compact karaoke-ready design and 7-band EQ make it more adaptable indoors than the earlier Encore.

Cons: It still lacks some upper-bass punch and cannot match the scale of the larger PartyBoxes. The main value is compact karaoke convenience rather than full-range party output.

Full JBL Partybox Encore 2 review and specifications →

Amplifier Power100W RMS
AppYes (JBL PartyBox app)
Aux InputYes
Battery Life15 hours (Manufacturer specified)
Bluetooth CodecsSBC
Bluetooth Version5.4
Built-in MicrophoneNo
Digital Aux InputNo
Dimensions12.6" x 13.3" x 10.4" (319.5 x 338.6 x 263 mm)
Drivers1x 135mm (5.25") woofer + 2x 20mm (0.75") dome tweeters
EQYes (7 band App EQ)
IP RatingIPX4
LightsYes
Maximum SPL110dB (measured by Alan Ross Reviews)
OmnidirectionalNo
Party ModeYes (Auracast)
Power BankYes (USB-C)
Power InputAC Power cord
Removable BatteryYes
StereoYes
TWSYes
USB PlaybackYes
Weight14.1 lbs (6.4 kg)
Wireless MicrophonesYes 2 Included
Check current price at Samsclub →Search eBay for JBL Partybox Encore 2 →

Yeahbox Sonic Boom Ultra: $349.20 Amazon eBay

Yeahbox Sonic Boom Ultra ranking card

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 Power320W RMS / 500W Peak
AppYes
Aux InputYes
Battery Capacity45000mAh (Reviewer estimated)
Bluetooth CodecsSBC (inferred; additional codecs unverified)
Bluetooth Version6.0
Digital Aux InputNo
Dimensions23.4" x 9.8" x 12.3" (595 x 248 x 313 mm)
Drivers6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way
EQYes (Country, Classic, and custom app EQ; custom settings don't persist after the app closes)
IP RatingIPX6
InputsHDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic
LightsYes
MicroSD PlaybackYes
OmnidirectionalNo
Party ModeNo (TWS stereo pairing of 2 units only, no Auracast)
Power InputUSB-C (60W fast charging)
StereoYes
TWSYes
USB PlaybackYes
Weight24.3 lbs (11 kg)
Check current price at Amazon ($349.20) →Search eBay for Yeahbox Sonic Boom Ultra →