Short answer: the Onyx Studio 6 is the better choice for listeners who want a warm, bassy compact speaker, while the Boom 2 Plus is the lighter boombox with greater tuning potential. Harman Kardon is 13 of 90, and Soundcore is 36 of 90.
The Onyx Studio 6 has a warm signature and was preferred slightly to the newer Onyx 7 by Oluv, but its eight-hour medium-volume battery estimate and limited loudness restrict outdoor versatility. The Boom 2 Plus is more portable and can benefit substantially from EQ, yet its default treble is rolled off and upper bass is pronounced.
Buy the Harman Kardon Onyx Studio 6 if you want the warmer, more relaxed sound and listen mostly at moderate levels.
Buy the Soundcore Boom 2 Plus if carrying convenience and the option to tune the sound with EQ are more valuable.
Battery life favors the Soundcore Boom 2 Plus: rated for 20 hours against 8 hours for the Harman Kardon Onyx Studio 6.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Onyx Studio 6 | Soundcore Boom 2 Plus | |
|---|---|---|
| Price | $130 Discontinued | $179.99 |
| Ranked | #13 of 90 in Boombox Size Portable Bluetooth Speakers | #36 of 90 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | 37Hz | 39Hz |
| Battery Life | 8 hours (Manufacturer specified) | 20 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| IP Rating | IPX7 | IPX7 |
| Bluetooth Latency | 180ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | 111dB (measured by Alan Ross Reviews) |
| Party Mode | Yes (Wireless Dual Sound) | Yes (PartyCast 2.0) |
| Power Input | DC Barrel Connector (19V/2A) | USB-C |
| Stereo | No | Yes |
| Omnidirectional | No | No |
| TWS | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) | Yes |
| Weight | 6.5 lbs (2.94 kg) | 8.4 lbs (3.8 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC, AAC |
| App | No | Yes |
| EQ | No | Yes (Pro EQ + presets) |
| Power Bank | No | Yes (USB-C, 5V/2A) |
| USB Playback | No | No |
| Bluetooth Version | 4.2 | 5.3 |
| Amplifier Power | 50W RMS | 140W |
| Dimensions | 5” x 11.5” x 11.2” (128 x 291 x 284 mm) | 17.3” x 9.1” x 5.9” (440 x 230 x 150 mm) |
| Drivers | 1x 120mm (4.7”) woofer + 1x 25mm (1”) tweeter + 1x passive radiator | 2x 114mm (4.5”) woofers + 2x 19mm (0.75”) tweeters |
| Digital Aux Input | No | No |
| Strap | No | Yes (detachable strap) |
| MicroSD Playback | - | No |
| Lights | - | Yes |
Related Speaker Comparisons
More worthwhile head-to-heads for Harman Kardon Onyx Studio 6:
- Tribit Stormbox Blast vs Harman Kardon Onyx Studio 6
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 6
- JBL Partybox Encore 2 vs Harman Kardon Onyx Studio 6
- JBL Partybox Encore Essential 2 vs Harman Kardon Onyx Studio 6
- JBL Partybox Encore vs Harman Kardon Onyx Studio 6
Prices on this page were last checked October 3, 2026 at 10:26 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 6: $130 Discontinued Amazon eBay
Newer model: the Harman Kardon Onyx Studio 9, ranked lower, rated 4.1/5.
Pros: Harman Kardon Onyx Studio 6 uses a 120mm woofer, 25mm tweeter and passive radiator. Its 2.94 kg, claimed 8 hours (Manufacturer specified) battery life, IPX7 protection, aux input and up to 96dB make it a practical option for its intended room or portable use. Measured bass extension of 37Hz (-10dB).
Cons: Bass is limited by its 37Hz specification. There is no companion app. No EQ adjustment. Warm tuning with boosted bass, and not as loud as others. Discontinued.
Full Harman Kardon Onyx Studio 6 review and specifications →
| Amplifier Power | 50W RMS |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 37Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 180ms |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 5” x 11.5” x 11.2” (128 x 291 x 284 mm) |
| Drivers | 1x 120mm (4.7”) woofer + 1x 25mm (1”) tweeter + 1x passive radiator |
| EQ | No |
| IP Rating | IPX7 |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Wireless Dual Sound) |
| Power Bank | No |
| Power Input | DC Barrel Connector (19V/2A) |
| Stereo | No |
| Strap | No |
| TWS | Yes (see https://www.reddit.com/r/Bluetooth_Speakers/comments/w339x5/how_to_harman_kardon_onyx_studio_5_6_dual_sound/) |
| USB Playback | No |
| Weight | 6.5 lbs (2.94 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Onyx Studio 7 vs Onyx Studio 6 - massive deep bass battle 😁 More from alanrossreviews →
- That Speaker Guy: Harman Kardon Onyx Studio 6 vs Devialet Mania
- Ezekielo: Citation 200 vs Onyx Studio 6 vs Bose Portable Speaker Sound Comparison
- Alan Ross Reviews: Harman Kardon Go+ Play 2 mini or Onyx Studio 6 - best speaker for bass?
- Alan Ross Reviews: Ultimate HK Onyx Studio speaker review and comparison! 8 speakers!
- Head-to-Head Comparisons
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 8
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 7
- Harman Kardon Onyx Studio 6 vs Harman Kardon Onyx Studio 9
- Harman Kardon Onyx Studio 6 vs Yeahbox Sonic Boom Ultra
- Harman Kardon Onyx Studio 6 vs Vifa Copenhagen 2.0
- Harman Kardon Onyx Studio 6 vs Zealot ZE51
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- Harman Kardon Onyx Studio 6 vs JBL Partybox Encore Essential
- See all 57 comparisons
Soundcore Boom 2 Plus: $179.99 Amazon B&H Photo Video eBay
Older model: the Soundcore Motion Boom+ (ranked lower, rated 2.9/5).
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. Measured bass extension of 39Hz (-10dB).
Cons: Warm tuning meaning a rolled off treble and some upper bass boost. Reasonably deep bass, but not as good as the top ranked.
Full Soundcore Boom 2 Plus review and specifications →
| Amplifier Power | 140W |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Bass Extension (-10dB) | 39Hz |
| Battery Life | 20 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 17.3” x 9.1” x 5.9” (440 x 230 x 150 mm) |
| Drivers | 2x 114mm (4.5”) woofers + 2x 19mm (0.75”) tweeters |
| EQ | Yes (Pro EQ + presets) |
| IP Rating | IPX7 |
| Lights | Yes |
| Maximum SPL | 111dB (measured by Alan Ross Reviews) |
| MicroSD Playback | No |
| Omnidirectional | No |
| Party Mode | Yes (PartyCast 2.0) |
| Power Bank | Yes (USB-C, 5V/2A) |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | Yes (detachable strap) |
| TWS | Yes |
| USB Playback | No |
| Weight | 8.4 lbs (3.8 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: This sounds totally different now! Soundcore Boom Plus 2 firmware 03.10 More from alanrossreviews →
- Alan Ross Reviews: Soundcore Boom 2 Plus Review - worst boombox speaker under $400?
- Jay’s Straight Up Reviews & More: Soundcore Boom 2 Plus VS Tribit Stormbox Blast 🛜 Boombox Basement Battle 📊Custom EQ 🔥Who You Got? More from JaysStraightUpReviews →
- Picky Audio: SO CLOSE! Soundcore Boom 2 Plus vs JBL Boombox 3 More from pickyaudio →
- Picky Audio: Extended Sound Test (Soundcore Boom 2 Plus vs JBL Boombox 3)
- Jay’s Straight Up Reviews & More: NEW RELEASE! Soundcore Boom 2 Plus vs Motion Boom Plus🤯Stock EQ, Bass^ Enabled🤜🤛 A Family Feud😆
- GYMCADDY: Soundcore Boom 2 Plus Showcase - Lots Of Bass In A Small Package More from GYMCADDY →
- EL JEFE REVIEWS: Soundcore Boom 2 Plus 💥 BIGGER & BADDER! More from ELJefeReviews →
- Jagist reviews: Zealot S95 Vs Soundcore Boom 2 Plus!!! More from Jagistreviews →
- Head-to-Head Comparisons
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