Short answer: the Zealot ZE51. It ranks #16 of 113 boombox speakers by sound quality (rated 4.1/5); the Teufel Boomster 4 ranks #50 (rated 3.4/5).
The Zealot ZE51 is the better-sounding pick. A big stereo boombox with clean, wide sound and low distortion at high volume for outdoor parties. The catch: The Zealot ZE41 still wins on raw bass depth and price.
The Teufel Boomster 4 is the longer-running, lighter option. A stereo boombox with DAB+ and FM radio, a long battery, splash resistance and a remote with treble control. It is rated for 23 hours of battery against 4 for the Zealot ZE51. At 8.3 lbs (3.75 kg) it weighs much less than the Zealot ZE51 at 26 lbs (11.81 kg). Watch for: Side by side with the Teufel Boomster 2021 the sound barely changed, and it has a little less deep bass.
Buy the Zealot ZE51. It is rated higher for sound quality than the Teufel Boomster 4.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Prices on this page were last checked November 14, 2026 at 6:17 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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Specifications Side By Side
| Zealot ZE51 | Teufel Boomster 4 | |
|---|---|---|
| Price | $235.33 after coupon | €249.99 |
| Ranked | #16 of 113 in Boombox Size Portable Bluetooth Speakers | #50 of 113 in Boombox Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | Yes | Yes |
| Battery Capacity | 48000mAh (12x4000mAh) | - |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | 5.0 |
| Dimensions | 22.1” x 9.4” x 13” (562 x 238 x 331 mm) | 7.1”H x 14.6”W x 5.8”D (180 x 370 x 148 mm) |
| EQ | Yes (Hi-Res, 3D Surround, Extra Bass, Vocal and other sound modes) | Yes (treble control) |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) | - |
| IP Rating | IPX5 | IPX5 |
| Microphone Input | Yes (Karaoke mode) | - |
| MicroSD Playback | Yes | - |
| Amplifier Power | 250W | 42W RMS |
| Power Bank | Yes (USB-A + USB-C) | No |
| Power Input | Type-C | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | - |
| Weight | 26 lbs (11.81 kg) | 8.3 lbs (3.75 kg) |
| Digital Aux Input | No | - |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | aptX HD, AAC, SBC |
| Drivers | 1x 133mm + 2x 93mm + 2x 45mm | 2x 20mm tweeters + 2x 65mm midrange drivers + 1x 110mm (4.3”) woofer, passive bass radiators |
| Battery Life | 4 hours (Manufacturer specified) | 23 hours (Manufacturer specified) |
| Strap | Yes (strap) | No |
| FM Tuner | - | Yes (plus DAB+) |
Where the Ratings Come From
- Zealot ZE51: reviews by J_Strat Battles.
- Teufel Boomster 4: reviews by Dominik and Mateusz Cholewa.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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