Harman Kardon Onyx Studio 8 vs Soundcore Motion Boom+

Last updated: August 28, 2026

Short answer: the Harman Kardon Onyx Studio 8 on measured sound quality, the Soundcore Motion Boom+ on price. The Harman Kardon Onyx Studio 8 ranks #10 of 73 boombox speakers at $159.99. The Soundcore Motion Boom+ ranks #47 at $140, $19.99 cheaper.

What the Harman Kardon Onyx Studio 8 offers: Warm sound with boosted bass. Watch for: Not as loud as others. No water rating.

What the Soundcore Motion Boom+ offers: 80W stereo from dual 30W woofers + dual 10W tweeters with titanium drivers for treble clarity. 13,400mAh battery for 20 hours (12-15 at high volume). IP67 waterproof, floats, rugged build inspires confidence. Bluetooth 5.3 multipoint pairing, Soundcore app EQ, PartyCast 2.0 mode. USB-C input, USB-A output for powerbank. Watch for: Default presets are all warm sounding with rolled off treble. Will need a custom EQ to get closer to neutral. A shrill sounding 6khz peak comes out when volume is above about 60%. Not much deeper bass than a Motion Boom and a lot less deep bass than other speakers in the class.

Buy the Harman Kardon Onyx Studio 8 if sound quality is the priority over the price, or the Soundcore Motion Boom+ if the price is the priority over sound quality.

There is a real battery-life gap here: the Soundcore Motion Boom+ is rated for 20 hours, the Harman Kardon Onyx Studio 8 only 8 hours.

Water resistance is not close: the Soundcore Motion Boom+ is rated at IP67 (brief submersion), well ahead of the Harman Kardon Onyx Studio 8 at no water resistance.

Buy the Harman Kardon Onyx Studio 8 at Amazon ($159.99) →Buy the Soundcore Motion Boom+ at Amazon ($140) →

Harman Kardon Onyx Studio 8 vs Soundcore Motion Boom+

Specifications Side By Side

Harman Kardon Onyx Studio 8 Soundcore Motion Boom+
Price$159.99$140 after $40 coupon, Discontinued
Ranked#10 of 73 in Boombox Size Portable Bluetooth Speakers#47 of 73 in Boombox Size Portable Bluetooth Speakers
Aux InputYesYes
Aux Latency42ms17ms
Bass Extension (-10dB)35Hz52Hz
Battery Life8 hours (Manufacturer specified)20 hours (Manufacturer specified)
Built in MicrophoneYesNo
IP RatingNoneIP67
Bluetooth Latency175ms33ms
Max Volume96dB108dB
Power InputDC Barrel Connector (19V/2.1A)USB-C
StereoYesYes
OmnidirectionalNoNo
TWSYesYes
Weight7.3 lbs / 3.3 kg5.3 lbs / 2.4 kg
AppYes (Harman Kardon One app)Yes (Soundcore app)
Bluetooth CodecsSBCSBC
Power BankNoYes (USB-A, 5V/2.1A)
EQYes (App EQ)Yes (App EQ)
Party ModeNoYes (PartyCast up to 100 speakers)
USB PlaybackNoNo
Bluetooth Version5.25.3
Output Power50W RMS80W
Dimensions10.6" x 11.9" x 6.3" (268 x 302.5 x 159.5 mm)15.1" x 5.1" x 7.7" (384 x 130 x 196 mm)
Drivers2x 75mm woofers + 2x 20mm tweeters30W: Dual drivers
Digital Aux InputNoNo
Discontinued-Yes
Buy the Harman Kardon Onyx Studio 8 at Amazon ($159.99) →Buy the Soundcore Motion Boom+ at Amazon ($140) →

Other pairings from the same speaker class worth checking:

Prices on this page were last checked August 27, 2026 at 10:09 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

Harman Kardon Onyx Studio 8: $159.99 Amazon eBay

Harman Kardon Onyx Studio 8 ranking card

Pros: Warm sound with boosted bass.

Cons: Not as loud as others. No water rating.

Full Harman Kardon Onyx Studio 8 review and specifications →

AppYes (Harman Kardon One app)
Aux InputYes
Aux Latency42ms
Bass Extension (-10dB)35Hz
Battery Life8 hours (Manufacturer specified)
Bluetooth CodecsSBC
Bluetooth Latency175ms
Bluetooth Version5.2
Built in MicrophoneYes
Digital Aux InputNo
Dimensions10.6" x 11.9" x 6.3" (268 x 302.5 x 159.5 mm)
Drivers2x 75mm woofers + 2x 20mm tweeters
EQYes (App EQ)
IP RatingNone
Max Volume96dB
OmnidirectionalNo
Output Power50W RMS
Party ModeNo
Power BankNo
Power InputDC Barrel Connector (19V/2.1A)
StereoYes
TWSYes
USB PlaybackNo
Weight7.3 lbs / 3.3 kg
Check current price at Amazon ($159.99) →Search eBay for Harman Kardon Onyx Studio 8 →

Soundcore Motion Boom+: $140 after $40 coupon, Discontinued Amazon eBay

Soundcore Motion Boom+ ranking card

Pros: 80W stereo from dual 30W woofers + dual 10W tweeters with titanium drivers for treble clarity. 13,400mAh battery for 20 hours (12-15 at high volume). IP67 waterproof, floats, rugged build inspires confidence. Bluetooth 5.3 multipoint pairing, Soundcore app EQ, PartyCast 2.0 mode. USB-C input, USB-A output for powerbank.

Cons: Default presets are all warm sounding with rolled off treble. Will need a custom EQ to get closer to neutral. A shrill sounding 6khz peak comes out when volume is above about 60%. Not much deeper bass than a Motion Boom and a lot less deep bass than other speakers in the class. Discontinued.

Full Soundcore Motion Boom+ review and specifications →

AppYes (Soundcore app)
Aux InputYes
Aux Latency17ms
Bass Extension (-10dB)52Hz
Battery Life20 hours (Manufacturer specified)
Bluetooth CodecsSBC
Bluetooth Latency33ms
Bluetooth Version5.3
Built in MicrophoneNo
Digital Aux InputNo
Dimensions15.1" x 5.1" x 7.7" (384 x 130 x 196 mm)
DiscontinuedYes
Drivers30W: Dual drivers
EQYes (App EQ)
IP RatingIP67
Max Volume108dB
OmnidirectionalNo
Output Power80W
Party ModeYes (PartyCast up to 100 speakers)
Power BankYes (USB-A, 5V/2.1A)
Power InputUSB-C
StereoYes
TWSYes
USB PlaybackNo
Weight5.3 lbs / 2.4 kg
Check current price at Amazon ($140) →Search eBay for Soundcore Motion Boom+ →