Yeahbox Sonic Boom Ultra vs W-King X20S

Last updated: October 5, 2026

Short answer: the Yeahbox Sonic Boom Ultra for better sound quality, the W-King X20S for the lower price. The Yeahbox Sonic Boom Ultra ranks #11 of 91 boombox speakers, rated 4.2/5, at $388. The W-King X20S ranks #30, rated 3.8/5, at $150.99, $237.01 cheaper.

Yeahbox Sonic Boom Ultra vs W-King X20S

The Yeahbox Sonic Boom Ultra is the better-sounding choice. 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. 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 W-King X20S is the lighter option. Clearer and smoother than the larger W-King X20 at about half its size and weight, and in side by side tests it held its own against the Harman Kardon Go + Play 3, with nicer, more exposed mids and more volume. At 13.8 lbs (6.25 kg) it weighs much less than the Yeahbox Sonic Boom Ultra at 24.3 lbs (11 kg). The catch: Less bass and depth than the X20 and about 3dB quieter, and at maximum volume its mids and highs start to drown out the bass.

Buy the Yeahbox Sonic Boom Ultra if sound quality matters more than the price. Buy the W-King X20S if the price matters more than sound quality.

Still deciding? The full Portable Bluetooth rankings cover every ranked option.

Check Yeahbox Sonic Boom Ultra price at Amazon ($388.00) →Check W-King X20S price at AliExpress ($150.99) →

Specifications Side By Side

Yeahbox Sonic Boom Ultra W-King X20S
Price$388.00$150.99
Ranked#11 of 91 in Boombox Size Portable Bluetooth Speakers#30 of 91 in Boombox Size Portable Bluetooth Speakers
AppYes-
Aux InputYesYes
Battery Capacity45000mAh (Reviewer estimated)-
BluetoothYesYes
Bluetooth Version6.05.4
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)-
InputsHDMI ARC (in/out, usable as a TV soundbar), AUX in/out, USB drive, microSD, optional wired mic-
IP RatingIPX6IPX7
MicroSD PlaybackYesYes
Amplifier Power320W RMS / 500W Peak140W RMS (180W peak)
Party ModeNo (TWS stereo pairing of 2 units only, no Auracast)-
Power InputUSB-C (60W fast charging)-
StereoYes-
OmnidirectionalNoNo
TWSYesYes
USB PlaybackYesYes
Weight24.3 lbs (11 kg)13.8 lbs (6.25 kg)
Digital Aux InputNo-
Bluetooth CodecsSBC (inferred; additional codecs unverified)-
LightsYes-
Battery Life24 hours (Manufacturer specified)-
StrapNoYes (detachable shoulder strap)
Built-in Microphone-Yes
FM Tuner-Yes
Check Yeahbox Sonic Boom Ultra price at Amazon ($388.00) →Check W-King X20S price at AliExpress ($150.99) →

How Yeahbox Sonic Boom Ultra compares with other leading options:

Prices on this page were last checked October 4, 2026 at 9:58 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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The Two Speakers In Full

Yeahbox Sonic Boom Ultra: $388.00 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)
Battery Life24 hours (Manufacturer specified)
BluetoothYes
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
StrapNo
TWSYes
USB PlaybackYes
Weight24.3 lbs (11 kg)
Check current price at Amazon ($388.00) →Search eBay for Yeahbox Sonic Boom Ultra →

W-King X20S: $150.99 AliExpress W-King eBay

W-King X20S ranking card

Pros: Clearer and smoother than the larger W-King X20 at about half its size and weight, and in side by side tests it held its own against the Harman Kardon Go + Play 3, with nicer, more exposed mids and more volume. 140W RMS (180W peak), IPX7, Bluetooth 5.4, a built-in microphone, TF card, USB and aux playback, FM radio, a carry handle and a shoulder strap.

Cons: Less bass and depth than the X20 and about 3dB quieter, and at maximum volume its mids and highs start to drown out the bass. With a flat EQ the bass is cut off, so it needs the bass boost. The JBL PartyBox Encore Essential 2 sounded better in a direct comparison. Sold direct from W-King in the US.

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Full W-King X20S review and specifications →

Amplifier Power140W RMS (180W peak)
Aux InputYes
BluetoothYes
Bluetooth Version5.4
Built-in MicrophoneYes
FM TunerYes
IP RatingIPX7
MicroSD PlaybackYes
OmnidirectionalNo
StrapYes (detachable shoulder strap)
TWSYes
USB PlaybackYes
Weight13.8 lbs (6.25 kg)
Check current price at AliExpress ($150.99) →Check current price at W-King ($199.99) →Search eBay for W-King X20S →
Top PickYeahbox Sonic Boom UltraAmazon • $388.00
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