Short answer: the Zealot ZE21. It ranks #18 of 112 boombox speakers by sound quality (rated 4.0/5) at $187.15 and is still sold new; the Diamondboxx M3 ranks #76 (rated 2.8/5) and is discontinued, so it is only an option used.
The Zealot ZE21 is the better-sounding, tougher choice. A rugged battery boombox with unusually deep bass, very long battery life, and stereo pairing for party scale sound. It is rated IPX6, while the Diamondboxx M3 has no water resistance. It links with other speakers (PartyAdd up to 100 speakers), which the Diamondboxx M3 cannot. It has an adjustable EQ, which the Diamondboxx M3 lacks. 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 Diamondboxx M3 is the lighter choice. A compact, very loud boombox with a powerful amplifier and a choice of large battery packs. At 11 lbs (5 kg) it weighs much less than the Zealot ZE21 at 20.4 lbs (9.27 kg). The catch: Despite its output, bass does not reach as deep as the best large portables and can distort when pushed hard.
Buy the Zealot ZE21. It is rated higher for sound quality; the Diamondboxx M3 is no longer sold new.
Want more options? Browse the full Portable Bluetooth rankings.
A rugged battery boombox with unusually deep bass, very long battery life, and stereo pairing for party scale sound.
A compact, very loud boombox with a powerful amplifier and a choice of large battery packs.
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Specifications Side By Side
| Zealot ZE21 | Diamondboxx M3 | |
|---|---|---|
| Price | $187.15 | $700 Discontinued |
| Ranked | #18 of 112 in Boombox Size Portable Bluetooth Speakers | #76 of 112 in Boombox Size Portable Bluetooth Speakers |
| App | No | No |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | 36Hz | - |
| Battery Life | 40 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| EQ | Yes (multiple modes) | No |
| IP Rating | IPX6 | None |
| MicroSD Playback | Yes | - |
| Party Mode | Yes (PartyAdd up to 100 speakers) | No |
| Power Input | USB-C | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 20.4 lbs (9.27 kg) | 11 lbs (5 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Power Bank | Yes (USB-A + USB-C) | No |
| USB Playback | Yes | No |
| Built-in Microphone | No | No |
| Amplifier Power | 250W | 200W RMS / 400W peak |
| Dimensions | 16.7” x 10.3” x 14.3” (424 x 262 x 363 mm) | 14.7” x 9” x 8” (373.4 x 228.6 x 203.2 mm) |
| Drivers | 130W subwoofer + 2x 50mm woofers + passive radiators | 3” woofer + tweeter array |
| Maximum SPL | 116dB (Manufacturer specified) | - |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.3 | 5.0 |
| FM Tuner | - | No |
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