These are not really the same size class, and that is the honest framing here. The Zealot S97 ranks #49 of 82 large speakers by sound quality at $65.86; the Ultimate Ears Boom 4 ranks #93 of 144 medium speakers by sound quality at $119.99.
The case for the Zealot S97: For a compact 3.3kg boombox, the S97 delivers unusually deep, clean-enough bass with a more sensible default balance than many inexpensive Zealot models. The catch: It is not especially loud for its size, battery life is only a claimed 12 hours, and the bass preset can swamp the rest of the music.
Why pick the Ultimate Ears Boom 4: IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. The tradeoff: Not much improvement over the old ones.
Buy the Zealot S97 at $65.86 for a large speaker, or the Ultimate Ears Boom 4 at $119.99 for a medium speaker instead.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Zealot S97 | Ultimate Ears Boom 4 | |
|---|---|---|
| Price | $65.86 with coupon YZZL10 | $119.99 |
| Ranked | #49 of 82 in Large Size Portable Bluetooth Speakers | #93 of 144 in Medium Size Portable Bluetooth Speakers |
| App | No | Yes |
| Aux Input | Yes | No |
| Battery Life | 12 hours (Manufacturer specified) | 15 hours (Manufacturer specified) |
| EQ | 3 EQ presets | Yes (via app) |
| IP Rating | IPX6 | IP67 |
| MicroSD Playback | Yes | - |
| Party Mode | Yes (PartyAdd up to 100 speakers) | - |
| Power Input | USB-C | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | No | Yes |
| Weight | 7.3 lbs (3.3 kg) | 1.4 lbs (620 g) |
| Bluetooth Codecs | SBC | SBC |
| Built-in Microphone | Yes | No |
| Power Bank | Yes (USB-A + USB-C) | No |
| Bluetooth Version | 5.2 | 5.1 |
| Dimensions | 12.6” x 7.3” x 5.9” (321 x 185 x 151 mm) | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Amplifier Power | 80W | - |
| Drivers | 2x 76mm (3”) woofers + 2x 38mm tweeters + 2x passive radiators | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| Digital Aux Input | No | No |
| Maximum SPL | - | 85dBC (Manufacturer specified) |
| Strap | - | Yes (built-in loop) |
Related Speaker Comparisons
How Zealot S97 compares with other leading options:
- Vifa Helsinki vs Zealot S97
- JBL Xtreme 5 vs Zealot S97
- Tribit Stormbox Lava vs Zealot S97
- Brane X vs Zealot S97
- Zealot S97 vs Minirig 4 with subwoofer
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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Speakers In Full
Zealot S97: $65.86 with coupon YZZL10 AliExpress eBay
Pros: For a compact 3.3kg boombox, the S97 delivers unusually deep, clean-enough bass with a more sensible default balance than many inexpensive Zealot models. It also brings IPX6 protection, aux and microSD playback, power-bank outputs, three EQ presets and PartyAdd linking.
Cons: It is not especially loud for its size, battery life is only a claimed 12 hours, and the bass preset can swamp the rest of the music. There is no app or fine-grained EQ, so the Vocal preset is the only practical way to improve the balance. It is still heavy for a speaker with this output ceiling.
Full Zealot S97 review and specifications →
| Amplifier Power | 80W |
|---|---|
| App | No |
| Aux Input | Yes |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 12.6” x 7.3” x 5.9” (321 x 185 x 151 mm) |
| Drivers | 2x 76mm (3”) woofers + 2x 38mm tweeters + 2x passive radiators |
| EQ | 3 EQ presets |
| IP Rating | IPX6 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | Yes (PartyAdd up to 100 speakers) |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | No |
| Weight | 7.3 lbs (3.3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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
- 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 DBSONO X-Blast F37
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 4
- Ultimate Ears Boom 4 vs Sony SRS-XE300
- See all 113 comparisons