Harman Kardon Onyx Studio 9 vs Soundcore Boom 2 Plus

Last updated: August 9, 2026

Short answer: the Harman Kardon Onyx Studio 9 for the higher ranking, the Soundcore Boom 2 Plus for the lower price. The Harman Kardon Onyx Studio 9 ranks #13 of 70 boombox speakers at $186.99. The Soundcore Boom 2 Plus ranks #26 at $169.99, $17 cheaper.

What the Harman Kardon Onyx Studio 9 gets right: Auracast multi-speaker connection alongside classic stereo pairing. The tradeoff: Slight recessed mids, boost in the upper mids, rolled off upper treble.

On the Soundcore Boom 2 Plus side: Quite a bit lighter than most of the other boombox size speakers. The tradeoff: Warm tuning meaning a rolled off treble and some upper bass boost.

Buy the Harman Kardon Onyx Studio 9 if the ranking matters more than the price. Buy the Soundcore Boom 2 Plus if the price matters more than the ranking.

Specifications Side By Side

Harman Kardon Onyx Studio 9 Soundcore Boom 2 Plus
Price$186.99$169.99
Ranked#13 of 70 in Boombox Size Portable Bluetooth Speakers#26 of 70 in Boombox Size Portable Bluetooth Speakers
Bass Extension (-10dB)41Hz39Hz
Max Volume101dB111dB
IP RatingNoneIPX7
Power InputUSB-CUSB-C
StereoYesYes
TWSYesYes
Weight9.3 lbs / 4.2 kg8.4 lbs / 3.8 kg
AppYes (Harman Kardon One app)Yes
Bluetooth CodecsSBCSBC, AAC
EQYes (App EQ)Yes (Pro EQ + presets)
Party ModeYes (Auracast)Yes (Partycast 2.0)
USB PlaybackNoNo
Bluetooth Version5.3-
Battery Life8 hours (Manufacturer specified)20 hours (Manufacturer specified)
Output Power50W RMS140W
Dimensions11.39" x 11.32" x 5.12" (289.2 x 287.5 x 130 mm)44cm x 23cm x 15cm
Drivers120mm woofer + 3x 20mm tweeters2x 114mm (4.5") woofers + 2x 19mm (0.75") tweeters
Aux Input-Yes
MicroSD Playback-No
Power Bank-Yes
Built in Microphone-Yes

The Two Speakers In Full

Harman Kardon Onyx Studio 9: $186.99 Amazon

Harman Kardon Onyx Studio 9 ranking card

Pros: Auracast multi-speaker connection alongside classic stereo pairing. Harman Kardon One app with EQ. USB-C charging, up from the previous generation’s AC power brick.

Cons: Slight recessed mids, boost in the upper mids, rolled off upper treble. Not as deep bass as previous Onyx Studio speakers.

AppYes (Harman Kardon One app)
Bass Extension (-10dB)41Hz
Battery Life8 hours (Manufacturer specified)
Bluetooth CodecsSBC
Bluetooth Version5.3
Dimensions11.39" x 11.32" x 5.12" (289.2 x 287.5 x 130 mm)
Drivers120mm woofer + 3x 20mm tweeters
EQYes (App EQ)
IP RatingNone
Max Volume101dB
Output Power50W RMS
Party ModeYes (Auracast)
Power InputUSB-C
StereoYes
TWSYes
USB PlaybackNo
Weight9.3 lbs / 4.2 kg
Check current price at Amazon ($186.99) →

Soundcore Boom 2 Plus: $169.99 Amazon Bhphotovideo

Soundcore Boom 2 Plus ranking card

Pros: Quite a bit lighter than most of the other boombox size speakers. This speaker will likely move up as we get a good EQ tune that makes it a lot more neutral.

Cons: Warm tuning meaning a rolled off treble and some upper bass boost. Reasonably deep bass, but not as good as the top ranked.

AppYes
Aux InputYes
Bass Extension (-10dB)39Hz
Battery Life20 hours (Manufacturer specified)
Bluetooth CodecsSBC, AAC
Built in MicrophoneYes
Dimensions44cm x 23cm x 15cm
Drivers2x 114mm (4.5") woofers + 2x 19mm (0.75") tweeters
EQYes (Pro EQ + presets)
IP RatingIPX7
Max Volume111dB
MicroSD PlaybackNo
Output Power140W
Party ModeYes (Partycast 2.0)
Power BankYes
Power InputUSB-C
StereoYes
TWSYes
USB PlaybackNo
Weight8.4 lbs / 3.8 kg
Check current price at Amazon ($169.99) →Check current price at Bhphotovideo →

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Product prices and availability were last checked August 9, 2026 at 6:57 AM UTC 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.