Short answer: the Ultimate Ears Boom 4. It ranks #88 of 136 medium speakers by sound quality at $105; the Harman Kardon Esquire 2 ranks #120 and costs $200, so there is little reason to consider the other one.
What the Ultimate Ears Boom 4 offers: 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. Watch for: Not much improvement over the old ones. Weak bass extension and thuddy bass. Gets distorted above 90%
What the Harman Kardon Esquire 2 offers: Doubles as a conferencing speakerphone with a 4-mic array and noise/echo cancellation. Flat, compact design packs easily. USB charge-out for topping off a phone. Watch for: Bass is weak, vocal and instrument separation is underwhelming and sounds tinny at high volume
Buy the Ultimate Ears Boom 4. It ranks higher for sound quality than the Harman Kardon Esquire 2 and costs less, which settles it without a real tradeoff to make.
The Harman Kardon Esquire 2 is not a sound-quality pick. It sits near the bottom of the 136 medium speakers; there are better options higher up.
Battery life favors the Ultimate Ears Boom 4: rated for 15 hours against 8 hours for the Harman Kardon Esquire 2.
There is a real gap in water resistance: the Ultimate Ears Boom 4 at IP67 (brief submersion) against the Harman Kardon Esquire 2, which has IPX4 (splashing).
Specifications Side By Side
| Ultimate Ears Boom 4 | Harman Kardon Esquire 2 | |
|---|---|---|
| Price | $105 | $200 Discontinued |
| Ranked | #88 of 136 in Medium Size Portable Bluetooth Speakers | #120 of 136 in Medium Size Portable Bluetooth Speakers |
| App | Yes | - |
| Battery Life | 15 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| IP Rating | IP67 | IPX4 |
| Power Input | USB-C | Micro USB |
| Stereo | Yes | No |
| Omnidirectional | No | No |
| Weight | 1.4 lbs / 620 g | 0.8 lbs / 0.35 kg |
| Bluetooth Version | 5.1 | 4.1 |
| Dimensions | 7.2" x 2.9" x 2.9" (184 x 73 x 73 mm) | 7.5" x 5.1" x 1.3" (190 x 130 x 34 mm) |
| Drivers | 2x 1.57" (40mm) active drivers + 2x 1.81" x 2.57" (46.1 x 65.2mm) passive radiators | 4x 1.25" (32mm) full-range drivers |
| TWS | Yes | No |
| EQ | Yes (via app) | - |
| Built in Microphone | No | Yes |
| Power Bank | No | Yes (USB-A) |
| Aux Input | No | Yes |
| Max Volume | 85dBC | - |
| Digital Aux Input | No | No |
| Output Power | - | 16W |
| Discontinued | - | Yes |
Related Speaker Comparisons
A few more comparisons worth a look in the same class:
- Sonos Roam 2 vs Ultimate Ears Boom 3
- Bose Soundlink Revolve+ vs Ultimate Ears Wonderboom
- Bose Soundlink Mini 2 vs Ultimate Ears Boom 3
- Ultimate Ears Boom 4 vs Ultimate Ears Megaboom 4
- JBL Charge 6 vs Ultimate Ears Boom 4
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
Ultimate Ears Boom 4: $105 Amazon eBay
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 →
| App | Yes |
|---|---|
| Aux Input | No |
| Battery Life | 15 hours (Manufacturer specified) |
| 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 |
| Max Volume | 85dBC |
| Omnidirectional | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| 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/Heritage 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 Sony SRS-XE300
- Ultimate Ears Boom 4 vs Tribit Stormbox
- See all 74 comparisons
Harman Kardon Esquire 2: $200 Discontinued eBay
Pros: Doubles as a conferencing speakerphone with a 4-mic array and noise/echo cancellation. Flat, compact design packs easily. USB charge-out for topping off a phone.
Cons: Bass is weak, vocal and instrument separation is underwhelming and sounds tinny at high volume. Discontinued.
Full Harman Kardon Esquire 2 review and specifications →
| Aux Input | Yes |
|---|---|
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Version | 4.1 |
| Built in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 7.5" x 5.1" x 1.3" (190 x 130 x 34 mm) |
| Discontinued | Yes |
| Drivers | 4x 1.25" (32mm) full-range drivers |
| IP Rating | IPX4 |
| Omnidirectional | No |
| Output Power | 16W |
| Power Bank | Yes (USB-A) |
| Power Input | Micro USB |
| Stereo | No |
| TWS | No |
| Weight | 0.8 lbs / 0.35 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Harman Kardon Esquire 2 vs Tribit Stormbox Mini
- Harman Kardon Esquire 2 vs LG Xboom XG5
- Harman Kardon Esquire 2 vs Ultimate Ears Roll 2
- Harman Kardon Esquire 2 vs LG Xboom Go PL5
- Harman Kardon Esquire 2 vs Sony SRS-XE200
- Harman Kardon Esquire 2 vs Tribit Stormbox Mini+
- Harman Kardon Esquire 2 vs Ultimate Ears Megaboom 4
- Harman Kardon Esquire 2 vs W-King D8 Mini
- See all 71 comparisons