Short answer: the Zealot S78, if you are buying new, though neither ranks well in its class. The Diamondboxx M3 ranks higher than it (#76 vs #110 of 112 boombox speakers, 2.8/5 vs 2.0/5) but is discontinued, so only consider it used; the Zealot S78 is still sold new at $91.38. Both are rated below 3.0/5 among the 112 boombox speakers, so if sound quality matters, consider the Tribit Stormbox Blast instead, ranked #2 at $179.99.
The Diamondboxx M3 is the better-sounding choice. A compact, very loud boombox with a powerful amplifier and a choice of large battery packs. The tradeoff: Despite its output, bass does not reach as deep as the best large portables and can distort when pushed hard.
The Zealot S78 is the tougher choice. A loud, rugged party speaker with full waterproofing, a power bank and wireless pairing for outdoor parties. It is rated IP67, while the Diamondboxx M3 has no water resistance. It has an adjustable EQ, which the Diamondboxx M3 lacks. The catch: At high volume, reviews report distortion and fluctuating level, so its headline power is more useful below its maximum setting.
Buy the Zealot S78, since the Diamondboxx M3 is discontinued and only worth hunting down used.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
A compact, very loud boombox with a powerful amplifier and a choice of large battery packs.
A loud, rugged party speaker with full waterproofing, a power bank and wireless pairing for outdoor parties.
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Specifications Side By Side
| Diamondboxx M3 | Zealot S78 | |
|---|---|---|
| Price | $700 Discontinued | $91.38 |
| Ranked | #76 of 112 in Boombox Size Portable Bluetooth Speakers | #110 of 112 in Boombox Size Portable Bluetooth Speakers |
| Bluetooth Version | 5.0 | 5.3 |
| Aux Input | Yes | Yes |
| Battery Life | 40 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| IP Rating | None | IP67 |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Weight | 11 lbs (5 kg) | 9.7 lbs (4.4 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| App | No | No |
| EQ | No | Yes (multiple modes) |
| TWS | Yes | Yes |
| Party Mode | No | No |
| Power Bank | No | Yes (USB-A) |
| USB Playback | No | Yes |
| Built-in Microphone | No | No |
| Power Input | USB-C | USB-C |
| FM Tuner | No | - |
| Amplifier Power | 200W RMS / 400W peak | 120W RMS / 150W peak |
| Dimensions | 14.7” x 9” x 8” (373.4 x 228.6 x 203.2 mm) | 16.1” x 6.6” x 7.3” (410 x 167 x 185 mm) |
| Drivers | 3” woofer + tweeter array | 2x ~120mm (4.72”) woofers + 2x ~42mm tweeters + 2x passive radiators |
| Digital Aux Input | No | No |
| MicroSD Playback | - | Yes |
| Strap | - | Yes (detachable shoulder strap) |
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