Short answer: the Harman Kardon Luna. It ranks #26 of 175 medium speakers by sound quality, rated 4.0/5, at $290.99. The Ultimate Ears Boom 4 ranks #113, rated 2.9/5, at $129.99, $161 cheaper, a saving that is not big enough to make up the sound-quality gap.
The Harman Kardon Luna is the better-sounding choice. The sound is fairly balanced apart from the boosted bass. Watch for: Boosted bass, and less detailed than higher-ranked speakers.
The Ultimate Ears Boom 4 is the lighter option. IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. At 1.4 lbs (620 g) it weighs much less than the Harman Kardon Luna at 2.5 lbs (1.13 kg). It has an adjustable EQ, which the Harman Kardon Luna lacks. It plays in stereo from a single unit, unlike the Harman Kardon Luna. The catch: Not much improvement over the old ones.
Buy the Harman Kardon Luna. It is rated higher for sound quality, and saving $161 with the Ultimate Ears Boom 4 does not make up for the sound-quality gap.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Harman Kardon Luna | Ultimate Ears Boom 4 | |
|---|---|---|
| Price | $290.99 | $129.99 |
| Ranked | #26 of 175 in Medium Size Portable Bluetooth Speakers | #113 of 175 in Medium Size Portable Bluetooth Speakers |
| App | No | Yes |
| Aux Input | No | No |
| Bass Extension (-10dB) | 57Hz | - |
| Battery Life | 12 hours (Manufacturer specified) | 15 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| EQ | No | Yes (via app) |
| IP Rating | IP67 | IP67 |
| MicroSD Playback | No | - |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | - |
| Weight | 2.5 lbs (1.13 kg) | 1.4 lbs (620 g) |
| Bluetooth Version | 5.3 | 5.1 |
| Dimensions | 8.3” x 3.1” x 3.1” (210 x 78 x 80 mm) | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Drivers | 48mm x 90mm woofer, 20mm tweeter | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| Frequency Response | 60Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 40W | - |
| Digital Aux Input | No | No |
| Built-in Microphone | - | No |
| Power Bank | - | No |
| Maximum SPL | - | 85dBC (Manufacturer specified) |
| Strap | - | Yes (built-in loop) |
Related Speaker Comparisons
More worthwhile head-to-heads for Harman Kardon Luna:
- Harman Kardon Luna vs EarFun Uboom L
- Soundcore Motion 300 vs Harman Kardon Luna
- Soundcore Motion+ vs Harman Kardon Luna
- Soundcore Boost “upgraded” 2021 vs Harman Kardon Luna
- Harman Kardon Luna vs Minirig 4
Prices on this page were last checked October 12, 2026 at 4:13 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 Luna: $290.99 Amazon $290.99 eBay
Newer model: the Harman Kardon Luna 2, ranked higher, rated 4.1/5, released Mar 2026. It adds app control and adjustable EQ. See every Harman Kardon Luna generation.
Pros: Harman Kardon Luna uses 48mm x 90mm woofer, 20mm tweeter. Its 1.13 kg, claimed 12 hours (Manufacturer specified) battery life, IP67 protection and mono playback make it a practical option for its intended room or portable use. The sound is fairly balanced apart from the boosted bass. Measured bass extension of 57Hz (-10dB).
Cons: Bass is limited by its 57Hz specification. There is no companion app. No EQ adjustment. Boosted bass, and less detailed than higher-ranked speakers.
Full Harman Kardon Luna review and specifications →
| Released | Sep 2023 (3 years ago) |
|---|---|
| Amplifier Power | 40W |
| App | No |
| Aux Input | No |
| Bass Extension (-10dB) | 57Hz |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 8.3” x 3.1” x 3.1” (210 x 78 x 80 mm) |
| Drivers | 48mm x 90mm woofer, 20mm tweeter |
| EQ | No |
| Frequency Response | 60Hz - 20kHz (Manufacturer specified) |
| IP Rating | IP67 |
| MicroSD Playback | No |
| Omnidirectional | No |
| Power Input | USB-C |
| Stereo | No |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 2.5 lbs (1.13 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Oluv Patreon: Harman Kardon Luna - sound demo More from Oluv’Sone →
- Alan Ross - The Anti Shill!: Onyx Studio 9 or Go Play 3? Or even the HK Luna?? More from alanrossreviews →
- Alan Ross Reviews: Beats Pill vs Harman Luna vs Bose Flex vs Soundcore Motion Plus
- Mateusz Cholewa: Harman Kardon Luna 2 UNBOXING vs HK Luna Short Test More from Mateusz Cholewa →
- Storytripper HD: Harman Kardon Luna vs Luna 2 More from storytripperhd →
- Storytripper HD: Klipsch Nashville vs Harman Kardon Luna vs Soundcore Motion 300
- Storytripper HD: Huawei Sound Joy 2 vs Tribit XSound Plus 2 vs Harman Kardon Luna
- Head-to-Head Comparisons
- Harman Kardon Luna vs Harman Kardon Luna 2
- Harman Kardon Luna vs Bogasing G4
- Harman Kardon Luna vs Bogasing M4
- Harman Kardon Luna vs Tribit Maxsound Plus
- Harman Kardon Luna vs JBL Charge 5 Wifi
- Harman Kardon Luna vs JBL Charge 5
- Harman Kardon Luna vs Tribit Xsound Mega
- Harman Kardon Luna vs Soundcore Boom 3i
- See all 136 comparisons
Ultimate Ears Boom 4: $129.99 Amazon $129.99 eBay
Older model: the Ultimate Ears Boom 3 (ranked lower, rated 2.9/5). See every Ultimate Ears Wonderboom, Boom and Megaboom generation.
Same family: the Ultimate Ears Wonderboom 4 (smaller model, ranked higher, rated 2.9/5) and the Ultimate Ears Megaboom 4 (larger model, ranked lower, rated 2.1/5).
Pros: IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. 15 hour battery. Customizable EQ and speaker-pairing via the UE app.
Cons: Not much improvement over the old ones. Weak bass extension and thuddy bass. Gets distorted above 90%
Full Ultimate Ears Boom 4 review and specifications →
| Released | Jun 2024 (2 years ago) |
|---|---|
| App | Yes |
| Aux Input | No |
| Battery Life | 15 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.1 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Drivers | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| EQ | Yes (via app) |
| IP Rating | IP67 |
| Maximum SPL | 85dBC (Manufacturer specified) |
| Omnidirectional | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 1.4 lbs (620 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ultimate Ears Boom 4 vs Ultimate Ears Boom 3
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom
- Ultimate Ears Boom 4 vs Klipsch Groove
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 2
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 3
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 4
- Ultimate Ears Boom 4 vs DBSONO X-Blast F37
- Ultimate Ears Boom 4 vs Sony SRS-XE300
- See all 139 comparisons