Yeahbox Sonic Boom Ultra vs JBL Partybox Encore

Q: Which is better, the Yeahbox Sonic Boom Ultra or the JBL Partybox Encore?

Short answer: the JBL Partybox Encore. It ranks #6 of 75 boombox speakers by sound quality at $230; the Yeahbox Sonic Boom Ultra ranks #10 and costs $349.20, which makes this an easy call rather than a real tradeoff.

Q: Should I buy the Yeahbox Sonic Boom Ultra or the JBL Partybox Encore?

Buy the JBL Partybox Encore. It ranks higher for sound quality than the Yeahbox Sonic Boom Ultra and costs less, which settles it without a real tradeoff to make.

Short answer: the JBL Partybox Encore. It ranks #6 of 75 boombox speakers by sound quality at $230; the Yeahbox Sonic Boom Ultra ranks #10 and costs $349.20, which makes this an easy call rather than a real tradeoff.

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 JBL Partybox Encore offers: JBL Partybox Encore uses 135mm woofer + 2x 20mm tweeters. Its 6.3 kg, claimed 6 hours (Manufacturer specified) battery life, IPX4 protection, aux input, up to 110dB and stereo playback make it a practical option for its intended room or portable use. Watch for: Bass is limited by its 38Hz specification.

Buy the JBL Partybox Encore. It ranks higher for sound quality than the Yeahbox Sonic Boom Ultra and costs less, which settles it without a real tradeoff to make.

Looking for alternatives? See the complete Portable Bluetooth rankings.

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

Specifications Side By Side

	Yeahbox Sonic Boom Ultra	JBL Partybox Encore
Price	$349.20	$230
Ranked	#10 of 75 in Boombox Size Portable Bluetooth Speakers	#6 of 75 in Boombox Size Portable Bluetooth Speakers
App	Yes	Yes (JBL PartyBox app)
Aux Input	Yes	Yes
Battery Capacity	45000mAh (Reviewer estimated)	-
Bluetooth Version	6.0	5.1
Dimensions	23.4" x 9.8" x 12.3" (595 x 248 x 313 mm)	10.9" x 12.9" x 11.5" (276 x 327 x 293 mm)
Drivers	6x9in racetrack woofer (200W) + 2x 4.5in midrange (40W each) + 2x tweeters (20W each), true 3-way	135mm woofer + 2x 20mm tweeters
EQ	Yes (Country, Classic, and custom app EQ; custom settings don't persist after the app closes)	Yes (3 band App EQ)
Inputs	HDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic	-
IP Rating	IPX6	IPX4
MicroSD Playback	Yes	-
Amplifier Power	320W RMS / 500W Peak	100W RMS
Party Mode	No (TWS stereo pairing of 2 units only, no Auracast)	Yes (PartyBoost up to 100 speakers)
Power Input	USB-C (60W fast charging)	AC Power cord
Stereo	Yes	Yes
Omnidirectional	No	No
TWS	Yes	Yes
USB Playback	Yes	Yes
Weight	24.3 lbs (11 kg)	13.9 lbs (6.3 kg)
Digital Aux Input	No	No
Bluetooth Codecs	SBC (inferred; additional codecs unverified)	SBC
Lights	Yes	-
Aux Latency	-	17ms
Bass Extension (-10dB)	-	38Hz
Battery Life	-	6 hours (Manufacturer specified)
Built-in Microphone	-	No
Bluetooth Latency	-	100ms
Maximum SPL	-	110dB (measured by Alan Ross Reviews)
Power Bank	-	Yes (USB-A, 5V/1.5A)
Wireless Microphones	-	Yes 2 Included

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

More top alternatives to JBL Partybox Encore:

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)

Check current price at Amazon ($349.20) →Search eBay for Yeahbox Sonic Boom Ultra →

JBL Partybox Encore: $230 Walmart eBay

Pros: JBL Partybox Encore uses 135mm woofer + 2x 20mm tweeters. Its 6.3 kg, claimed 6 hours (Manufacturer specified) battery life, IPX4 protection, aux input, up to 110dB and stereo playback make it a practical option for its intended room or portable use. Measured bass extension of 38Hz (-10dB).

Cons: Bass is limited by its 38Hz specification.

Full JBL Partybox Encore review and specifications →

Amplifier Power	100W RMS
App	Yes (JBL PartyBox app)
Aux Input	Yes
Aux Latency	17ms
Bass Extension (-10dB)	38Hz
Battery Life	6 hours (Manufacturer specified)
Bluetooth Codecs	SBC
Bluetooth Latency	100ms
Bluetooth Version	5.1
Built-in Microphone	No
Digital Aux Input	No
Dimensions	10.9" x 12.9" x 11.5" (276 x 327 x 293 mm)
Drivers	135mm woofer + 2x 20mm tweeters
EQ	Yes (3 band App EQ)
IP Rating	IPX4
Maximum SPL	110dB (measured by Alan Ross Reviews)
Omnidirectional	No
Party Mode	Yes (PartyBoost up to 100 speakers)
Power Bank	Yes (USB-A, 5V/1.5A)
Power Input	AC Power cord
Stereo	Yes
TWS	Yes
USB Playback	Yes
Weight	13.9 lbs (6.3 kg)
Wireless Microphones	Yes 2 Included

Check current price at Walmart →Search eBay for JBL Partybox Encore →

Specifications Side By Side

Related Speaker Comparisons

The Two Speakers In Full

Yeahbox Sonic Boom Ultra: $349.20 Amazon eBay

JBL Partybox Encore: $230 Walmart eBay