Short answer: the Zealot ZE21. It ranks #18 of 98 boombox speakers by sound quality, rated 4.0/5, at $247.41; the JBL Authentics 300 ranks #44, rated 3.5/5, and costs $499.95, so there is little reason to consider the other one.
The Zealot ZE21 is the better-sounding, deeper-bass choice. 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 bass reaches about 36Hz before falling 10dB, against 45Hz for the JBL Authentics 300. It is rated for 40 hours of battery against 8 for the JBL Authentics 300. It is rated IPX6, while the JBL Authentics 300 has no water resistance. The catch: 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 JBL Authentics 300 is the lighter pick. Integrates both Amazon Alexa and Google Assistant simultaneously (rare for smart speakers). At 10.8 lbs (4.9 kg) it weighs much less than the Zealot ZE21 at 20.4 lbs (9.27 kg). Watch for: Narrow sounding, bass not as deep as others.
Buy the Zealot ZE21. It is rated higher for sound quality than the JBL Authentics 300 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Zealot ZE21 | JBL Authentics 300 | |
|---|---|---|
| Price | $247.41 | $499.95 |
| Ranked | #18 of 98 in Boombox Size Portable Bluetooth Speakers | #44 of 98 in Boombox Size Portable Bluetooth Speakers |
| App | No | Yes |
| Aux Input | Yes | No |
| Bass Extension (-10dB) | 36Hz | 45Hz |
| Battery Life | 40 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| EQ | Yes (multiple modes) | Yes (App EQ) |
| IP Rating | IPX6 | None |
| MicroSD Playback | Yes | No |
| Party Mode | Yes (PartyAdd up to 100 speakers) | Yes (Wi-Fi Multi-Room) |
| Power Input | USB-C | AC Power cable |
| Stereo | Yes | Partially (1 woofer) |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 20.4 lbs (9.27 kg) | 10.8 lbs (4.9 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Power Bank | Yes (USB-A + USB-C) | No |
| USB Playback | Yes | Yes |
| Built-in Microphone | No | Yes |
| Amplifier Power | 250W | 100W |
| Dimensions | 16.7” x 10.3” x 14.3” (424 x 262 x 363 mm) | 13.5” x 7.7” x 7.1” (342 x 195.6 x 180.3 mm) |
| Drivers | 130W subwoofer + 2x 50mm woofers + passive radiators | 1” tweeter + 4” woofer + passive radiators |
| Maximum SPL | 116dB (Manufacturer specified) | 100dB (measured by Alan Ross Reviews) |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.3 | 5.3 |
| Wi-Fi | - | Yes |
| Voice Assistants | - | Amazon Alexa & Google Assistant (simultaneous) |
| Strap | - | No |
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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
Zealot ZE21: $247.41 Amazon $247.41 AliExpress $187.15 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 →
| Released | Dec 2024 (1 year ago) |
|---|---|
| Amplifier Power | 250W |
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 36Hz |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth | Yes |
| 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
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JBL Authentics 300: $499.95 Amazon $499.95 eBay
Same family: the JBL Authentics 200 (smaller model, rated 3.7/5) and the JBL Authentics 500 (larger model, rated 4.1/5).
Pros: Integrates both Amazon Alexa and Google Assistant simultaneously (rare for smart speakers). Retro seventies design with leather and Quadrex grille. 100-watt amp, carries well with leather-trimmed handle. Rechargeable battery rated ~8 hours. Measured bass extension of 45Hz (-10dB).
Cons: Narrow sounding, bass not as deep as others. Peaky upper mids. No TWS. No IP rating. Not as loud as others. Not much battery life.
Full JBL Authentics 300 review and specifications →
| Released | Sep 2023 (3 years ago) |
|---|---|
| Amplifier Power | 100W |
| App | Yes |
| Aux Input | No |
| Bass Extension (-10dB) | 45Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 13.5” x 7.7” x 7.1” (342 x 195.6 x 180.3 mm) |
| Drivers | 1” tweeter + 4” woofer + passive radiators |
| EQ | Yes (App EQ) |
| IP Rating | None |
| Maximum SPL | 100dB (measured by Alan Ross Reviews) |
| MicroSD Playback | No |
| Omnidirectional | No |
| Party Mode | Yes (Wi-Fi Multi-Room) |
| Power Bank | No |
| Power Input | AC Power cable |
| Stereo | Partially (1 woofer) |
| Strap | No |
| TWS | Yes |
| USB Playback | Yes |
| Voice Assistants | Amazon Alexa & Google Assistant (simultaneous) |
| Weight | 10.8 lbs (4.9 kg) |
| Wi-Fi | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- JOY‘s 🎧3D🔈Audio-Show: JBL Authentics 300 - sound quality test More from Oluv’Sone →
- Oluv Patreon: JBL Authentics 300 - update
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- Alan Ross Reviews: Not quite! JBL Authentics 300 review and sound test vs Boombox 3, Encore and Stormbox Blast More from alanrossreviews →
- Storytripper HD: W-King H330 vs JBL Authentics 300 More from storytripperhd →
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