Short answer: the Zealot ZE21. It ranks #19 of 75 boombox speakers at $549.95, ahead of the JBL Boombox 4’s #17 at $247.41, a $302.54 difference. Both Techder Audios and Jagist Reviews have put the two head-to-head on YouTube, and neither video makes a case for paying JBL’s premium.
The JBL name doesn’t buy better sound here. The Boombox 4’s own notes describe it as pretty overpriced for the category, and reviewers say it sounds worse out of the box than the Boombox 3 it replaced; its 7-band EQ helps close that gap but needs manual tuning to get there. Its one clear strength is pretty insane output capability for the size.
The ZE21 competes on value, not polish. It’s not a refined-sounding speaker either: reviewers describe it as a little rolled off up top and not well balanced through the rest of the range, with a bass EQ mode that runs bloated and muddy. What it does deliver is real bass output, a longer 40-hour battery life against the Boombox 4’s 28 hours, and a max volume that edges out the JBL (116dB vs 115dB), all for a fraction of the price.
The two also diverge on convenience features. The Boombox 4 has an app, USB-C digital audio input, and a more advanced LC3/AAC codec set; the ZE21 has a basic aux input, USB and microSD playback, and PartyAdd linking for up to 100 speakers. Neither has a meaningful edge on connectivity, they’re just built differently.
Buy the Zealot ZE21. It ranks higher, costs hundreds less, and nothing about the Boombox 4’s sound quality justifies the price gap.
Buy the JBL Boombox 4 only if the JBL ecosystem, IP68 rating, or its app-based EQ specifically matter more to you than saving money.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| JBL Boombox 4 | Zealot ZE21 | |
|---|---|---|
| Price | $549.95 | $187.15 |
| Ranked | #19 of 75 in Boombox Size Portable Bluetooth Speakers | #17 of 75 in Boombox Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | No | Yes |
| Bass Extension (-10dB) | 41Hz | 36Hz |
| Battery Life | 28 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| EQ | Yes (7 band) | Yes (multiple modes) |
| IP Rating | IP68 | IPX6 |
| Bluetooth Latency | AAC 144ms, SBC 48ms | - |
| Maximum SPL | 115dB (measured by Alan Ross Reviews) | 116dB (Manufacturer specified) |
| Party Mode | Yes (Auracast) | Yes (PartyAdd up to 100 speakers) |
| Power Input | AC Power cord | USB-C |
| Removable Battery | Yes | - |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Weight | 13.2 lbs (5.98 kg) | 20.4 lbs (9.27 kg) |
| Bluetooth Codecs | SBC, LC3, AAC | SBC |
| Bluetooth Version | 5.4 | 5.3 |
| Built-in Microphone | No | No |
| Power Bank | Yes (USB-C, up to 30W) | Yes (USB-A + USB-C) |
| TWS | Yes | Yes |
| Digital Aux Input | Yes (USB-C) | No |
| USB Playback | No | Yes |
| FM Tuner | No | - |
| Microphone Input | No | - |
| MicroSD Playback | No | Yes |
| Amplifier Power | 210W AC / 200W battery | 250W |
| Dimensions | 20.1" x 10.2" x 8.3" (510 x 260 x 210 mm) | 16.7" x 10.3" x 14.3" (424 x 262 x 363 mm) |
| Drivers | 2x 123mm woofers + 2x 20mm tweeters with passive radiators | 130W subwoofer + 2x 50mm woofers + passive radiators |
Related Speaker Comparisons
How Zealot ZE21 compares with other leading options:
- Tribit Stormbox Blast vs Zealot ZE21
- Harman Kardon Go + Play 3 vs Zealot ZE21
- JBL Partybox Encore 2 vs Zealot ZE21
- JBL Partybox Encore Essential 2 vs Zealot ZE21
- JBL Partybox Encore vs Zealot ZE21
Prices on this page were last checked September 23, 2026 at 11:24 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
JBL Boombox 4: $549.95 Amazon B&H Photo Video eBay
Pros: Pretty insane output capability for the size. Measured bass extension of 41Hz (-10dB).
Cons: Pretty overpriced for the category. Better than the Boombox 3 mostly because there are more 7 EQ bands instead of just 3 and it can be better tuned. Try Oluv’s EQ for it. Out of the box sounds worse than the Boombox 3. No Aux input.
Full JBL Boombox 4 review and specifications →
| Amplifier Power | 210W AC / 200W battery |
|---|---|
| App | Yes |
| Aux Input | No |
| Bass Extension (-10dB) | 41Hz |
| Battery Life | 28 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC, LC3, AAC |
| Bluetooth Latency | AAC 144ms, SBC 48ms |
| Bluetooth Version | 5.4 |
| Built-in Microphone | No |
| Digital Aux Input | Yes (USB-C) |
| Dimensions | 20.1" x 10.2" x 8.3" (510 x 260 x 210 mm) |
| Drivers | 2x 123mm woofers + 2x 20mm tweeters with passive radiators |
| EQ | Yes (7 band) |
| FM Tuner | No |
| IP Rating | IP68 |
| Maximum SPL | 115dB (measured by Alan Ross Reviews) |
| MicroSD Playback | No |
| Microphone Input | No |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Bank | Yes (USB-C, up to 30W) |
| Power Input | AC Power cord |
| Removable Battery | Yes |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | No |
| Weight | 13.2 lbs (5.98 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Boombox 3 - old one sounding better? 🤔 More from Oluv’Sone →
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Earfun UBoom X - sound test
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Boombox 3 - any improvement?
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 vs Partybox Encore 2 - outdoor loudness & basstest
- JOY‘s 🎧3D🔈Audio-Show: JBL Boombox 4 - finally a real BOOMbox from JBL 👏
- Alan Ross Reviews: JBL Boombox 4 HUMILIATES Brane X?! Ultimate Bass Battle! More from alanrossreviews →
- Alan Ross Reviews: JBL Boombox 4 Compared to Boombox 3 & 3 WiFi – Worth the Upgrade?
- Alan Ross Reviews: JBL Boombox 4 distortion fest bonanza! how bad can it be lol 🤣
- Jagist reviews: Jbl Boombox 4 Vs Zealot Ze21!!! More from Jagistreviews →
- Techder Audios: JBL Boombox 4 VS Zealot ZE21 BATTLE OF THE BOOMBOXES! More from techderaudios →
- Dominik Reviews: Zealot S89 vs JBL Boombox 4 - JBL Alternative? Sound Test More from Dominik Reviews →
- Jagist reviews: Jbl Boombox 4 Vs Zealot S89!!!
- Jagist reviews: Jbl Boombox 4 Vs Zealot S95!!!
- M1MTechChannel: Welche JBL Partybox ist die BESTE ? Alle Partyboxen im Vergleich | 2026 More from M1MTechChannel →
- M1MTechChannel: JBL BOOMBOX 4 - Einfach komplett GEISTESKRANK
- Head-to-Head Comparisons
- JBL Boombox 4 vs Zealot S89
- JBL Boombox 4 vs Harman Kardon Go + Play 2
- JBL Boombox 4 vs Harman Kardon Onyx Studio 5
- JBL Boombox 4 vs Zealot ZE41
- JBL Boombox 4 vs JBL Boombox 3 Wifi
- JBL Boombox 4 vs JBL Boombox 3
- JBL Boombox 4 vs Zealot ZE51
- JBL Boombox 4 vs Tribit Stormbox Blast 2
- See all 81 comparisons
Zealot ZE21: $187.15 Amazon Aliexpress eBay
Pros: The ZE21’s main attraction is unusually deep bass for a battery boombox: owner testing finds real output in the 40-50Hz region and audibility down toward the low 30s. Its TWS button can form a stereo pair with another compatible Zealot, and its large, rugged chassis gives it credible party-speaker scale. Measured bass extension of 36Hz (-10dB).
Cons: That deep-bass emphasis comes with a pronounced 60-110Hz kick-bass dip and over-loud 250-600Hz lower mids, which can make rock and pop sound hollow or boxy. The supplied sound modes do not fully correct the tuning; the most positive independent report required source-side parametric EQ. Treble is also soft and clarity trails better-tuned rivals.
Full Zealot ZE21 review and specifications →
| Amplifier Power | 250W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 36Hz |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.7" x 10.3" x 14.3" (424 x 262 x 363 mm) |
| Drivers | 130W subwoofer + 2x 50mm woofers + passive radiators |
| EQ | Yes (multiple modes) |
| IP Rating | IPX6 |
| Maximum SPL | 116dB (Manufacturer specified) |
| 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 | Yes |
| USB Playback | Yes |
| Weight | 20.4 lbs (9.27 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Jagist reviews: Jbl Boombox 4 Vs Zealot Ze21!!! More from Jagistreviews →
- Jagist reviews: Zealot Ze21 Vs Tribit Stormbox Blast 2!!!
- Techder Audios: JBL Boombox 4 VS Zealot ZE21 BATTLE OF THE BOOMBOXES! More from techderaudios →
- Jay’s Straight Up Reviews & More: Zealot ZE21 vs JBL Boombox 3 Tailgater Special @20ft. The Budget Beast Against the OG Boombox More from JaysStraightUpReviews →
- Head-to-Head Comparisons
- Zealot ZE21 vs Zealot ZE41
- Zealot ZE21 vs Zealot S89
- Zealot ZE21 vs Zealot ZE51
- Zealot ZE21 vs Harman Kardon Onyx Studio 9
- Zealot ZE21 vs Harman Kardon Go + Play 2
- Zealot ZE21 vs Harman Kardon Onyx Studio 7
- Zealot ZE21 vs Harman Kardon Onyx Studio 5
- Zealot ZE21 vs Harman Kardon Onyx Studio 6
- See all 56 comparisons