These sit in different size classes, so this is not a straight ranking comparison. The Ultimate Ears Boom 4 ranks #93 of 144 medium speakers by sound quality at $119.99; the Zealot S67 ranks #81 of 82 large speakers by sound quality at $70.94. Both are rated below 3.0/5 for their class (144 medium speakers and 82 large speakers), so if sound quality matters, look higher up the rankings.
Why pick the Ultimate Ears Boom 4: IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. The catch: Not much improvement over the old ones.
What the Zealot S67 does well: It offers a lot of practical hardware for a 2.4kg budget speaker: IPX6 water resistance, USB-C charging, aux and microSD playback, speakerphone, a claimed 20-hour battery and TWS pairing for a second unit. The tradeoff: Sound quality is the catch.
Buy the Ultimate Ears Boom 4 at $119.99 if you want a medium speaker. Buy the Zealot S67 at $70.94 if you want a large speaker instead.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Ultimate Ears Boom 4 | Zealot S67 | |
|---|---|---|
| Price | $119.99 | $70.94 |
| Ranked | #93 of 144 in Medium Size Portable Bluetooth Speakers | #81 of 82 in Large Size Portable Bluetooth Speakers |
| App | Yes | No |
| Battery Life | 15 hours (Manufacturer specified) | 20 hours (Manufacturer specified) |
| IP Rating | IP67 | IPX6 |
| Power Input | USB-C | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Weight | 1.4 lbs (620 g) | 5.3 lbs (2.4 kg) |
| Bluetooth Version | 5.1 | 5.2 |
| Dimensions | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) | 11.6” x 4.8” x 5.2” (294 x 122 x 132 mm) |
| Drivers | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators | 60W: Dual drivers + passive radiator |
| TWS | Yes | Yes |
| EQ | Yes (via app) | No |
| Built-in Microphone | No | Yes |
| Power Bank | No | No |
| Aux Input | No | Yes |
| Maximum SPL | 85dBC (Manufacturer specified) | - |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC | SBC |
| Strap | Yes (built-in loop) | - |
| MicroSD Playback | - | Yes |
| Party Mode | - | No |
| Amplifier Power | - | 60W |
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Prices on this page were last checked September 26, 2026 at 11:14 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: $119.99 Amazon eBay
Older model: the Ultimate Ears Boom 3 (rated 2.9/5).
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 →
| App | Yes |
|---|---|
| Aux Input | No |
| Battery Life | 15 hours (Manufacturer specified) |
| 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
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- 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
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- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 4
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Zealot S67: $70.94 AliExpress eBay
Pros: It offers a lot of practical hardware for a 2.4kg budget speaker: IPX6 water resistance, USB-C charging, aux and microSD playback, speakerphone, a claimed 20-hour battery and TWS pairing for a second unit. The large enclosure and dual-driver/passive-radiator layout can provide useful party-level volume.
Cons: Sound quality is the catch. Independent reviewer comparisons report obvious distortion once volume rises past roughly halfway, little true deep bass, and a rolled-off, low-detail treble. There is no app or real EQ to correct that balance, so its long feature list does not make it a good pick for attentive music listening.
Full Zealot S67 review and specifications →
| Amplifier Power | 60W |
|---|---|
| App | No |
| Aux Input | Yes |
| Battery Life | 20 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.6” x 4.8” x 5.2” (294 x 122 x 132 mm) |
| Drivers | 60W: Dual drivers + passive radiator |
| EQ | No |
| IP Rating | IPX6 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| Weight | 5.3 lbs (2.4 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Jay’s Straight Up Reviews & More: ZEALOT S-67 🦨 75w Bluetooth Speaker Review🤦🏼♂️ & Comparison With W-King X10. More from JaysStraightUpReviews →
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