Short answer: the Zealot ZE51. It ranks #16 of 89 boombox speakers by sound quality (rated 4.1/5); the Teufel Boomster 4 ranks #44 (rated 3.4/5).
Why pick the Zealot ZE51: Cleaner sound and a wider stereo soundstage than the Zealot ZE41, with less distortion at high volume for better instrumental detail and clarity. The tradeoff: The Zealot ZE41 still wins on raw bass depth and price.
The case for the Teufel Boomster 4: Warmer and more open than the Boomster 2021 it replaces, with nicer, less harsh highs, a wide stereo image from its three-way layout (two 20mm tweeters, two 65mm midrange drivers and a 110mm woofer with passive radiators) and good detail. Watch for: Side by side with the 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.
Specifications Side By Side
| Zealot ZE51 | Teufel Boomster 4 | |
|---|---|---|
| Price | $296.39 after coupon | €249.99 |
| Ranked | #16 of 89 in Boombox Size Portable Bluetooth Speakers | #44 of 89 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+) |
Related Speaker Comparisons
More worthwhile head-to-heads for Zealot ZE51:
- Zealot ZE51 vs Earfun Uboom X
- Zealot ZE51 vs Tribit Stormbox Blast
- Zealot ZE51 vs Harman Kardon Go + Play 3
- Zealot ZE51 vs JBL Partybox Encore 2
- JBL PartyBox On-The-Go 2 Plus vs Zealot ZE51
Prices on this page were last checked September 30, 2026 at 2:57 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 ZE51: $296.39 after coupon Amazon AliExpress eBay
Pros: Cleaner sound and a wider stereo soundstage than the Zealot ZE41, with less distortion at high volume for better instrumental detail and clarity.
Cons: The Zealot ZE41 still wins on raw bass depth and price. Large and heavy like the rest of the boombox class, and clarity still isn’t up to dedicated hi-fi speakers.
Full Zealot ZE51 review and specifications →
| Amplifier Power | 250W |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Battery Capacity | 48000mAh (12x4000mAh) |
| Battery Life | 4 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 22.1” x 9.4” x 13” (562 x 238 x 331 mm) |
| Drivers | 1x 133mm + 2x 93mm + 2x 45mm |
| EQ | Yes (Hi-Res, 3D Surround, Extra Bass, Vocal and other sound modes) |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) |
| IP Rating | IPX5 |
| MicroSD Playback | Yes |
| Microphone Input | Yes (Karaoke mode) |
| Omnidirectional | No |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | Type-C |
| Stereo | Yes |
| Strap | Yes (strap) |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 26 lbs (11.81 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Zealot ZE51 vs Zealot ZE41
- Zealot ZE51 vs Harman Kardon Onyx Studio 9
- Zealot ZE51 vs Zealot ZE21
- Zealot ZE51 vs Harman Kardon Onyx Studio 7
- Zealot ZE51 vs Zealot S89
- Zealot ZE51 vs Harman Kardon Onyx Studio 6
- Zealot ZE51 vs JBL Boombox 4
- Zealot ZE51 vs Harman Kardon Onyx Studio 8
- See all 79 comparisons
Teufel Boomster 4: €249.99 Teufel eBay
Older models: the Teufel Boomster 2021 (ranked lower, rated 3.4/5) and the Teufel Boomster NG (2017) (ranked lower, rated 3.2/5).
Pros: Warmer and more open than the Boomster 2021 it replaces, with nicer, less harsh highs, a wide stereo image from its three-way layout (two 20mm tweeters, two 65mm midrange drivers and a 110mm woofer with passive radiators) and good detail. Its new treble control and remote let you tame the top end. DAB+ and FM radio, a claimed 23 hours of battery at medium volume, IPX5, Bluetooth 5.0 with AAC and aptX HD, multipoint, an aux input, USB-C charging and stereo pairing.
Cons: Side by side with the Boomster 2021 the sound barely changed, and it has a little less deep bass. Against the Harman Kardon Go + Play 3 it sounds sharper and thinner, with weaker bass and a less natural stereo image, and its bass drops off at full volume. At 3.75 kg it is heavy for its size, it has no power bank output, and IPX5 is a step down from the older model’s IPX7.
Full Teufel Boomster 4 review and specifications →
| Amplifier Power | 42W RMS |
|---|---|
| App | No |
| Aux Input | Yes |
| Battery Life | 23 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | aptX HD, AAC, SBC |
| Bluetooth Version | 5.0 |
| Dimensions | 7.1”H x 14.6”W x 5.8”D (180 x 370 x 148 mm) |
| Drivers | 2x 20mm tweeters + 2x 65mm midrange drivers + 1x 110mm (4.3”) woofer, passive bass radiators |
| EQ | Yes (treble control) |
| FM Tuner | Yes (plus DAB+) |
| IP Rating | IPX5 |
| Omnidirectional | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| Weight | 8.3 lbs (3.75 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Mateusz Cholewa: Nowy TEUFEL Boomster 4 UNBOXING vs Boomster 3 Review in subtitles More from Mateusz Cholewa →
- Mateusz Cholewa: TEUFEL Boomster 4 vs HK Go Plus Play 3 & Opinion in Subtitles
- Dominik Reviews: Teufel BOOMSTER 4 vs BOOMSTER 2021 - No difference? Sound Battle! More from Dominik Reviews →
- Dominik Reviews: Teufel BOOMSTER 4 vs JBL Xtreme 4 - Not great for the size? Sound Test
- Dominik Reviews: Teufel BOOMSTER 4 vs Earfun UBOOM X - BASS!! - Sound Test
- Dominik Reviews: Teufel BOOMSTER 4 vs Bugani Brief Pro - Cheaper and Better! Sound Test
- Head-to-Head Comparisons
- Teufel Boomster 4 vs Teufel Boomster 2021
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- Teufel Boomster 4 vs W-King X20
- Teufel Boomster 4 vs Soundcore Boom 2 Plus
- Teufel Boomster 4 vs Onn Medium Party Speaker Gen 2
- Teufel Boomster 4 vs Tribit Stormbox Blast 2
- Teufel Boomster 4 vs JBL Partybox On the Go
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- See all 26 comparisons