Short answer: the Diamondboxx M3 on measured sound quality, the Zealot S78 on price. The Diamondboxx M3 ranks #53 of 75 boombox speakers at $700. The Zealot S78 ranks #75 at $159.68, $540.32 cheaper.
What the Diamondboxx M3 offers: An unusually compact 5kg high-output boombox, with a claimed 200W RMS Class A/B amplifier, 114dB maximum level, active crossovers and a choice of large battery packs. It has aux input, USB-C power and TWS pairing, while the aluminum heat sink is designed to sustain loud playback without thermal shutdown. Watch for: Despite its output, bass does not reach as deep as the best large portables and can distort when pushed hard. The treble-forward tuning can sound aggressive, there is no app or EQ to correct it, and the lack of a water rating makes it a poor match for poolside or rough-weather use.
What the Zealot S78 offers: A robust 4.4kg party speaker with claimed 120W RMS output, IP67 protection, USB-C charging, a power-bank function, aux, USB and microSD playback, TWS pairing and multiple EQ modes. Reviews find it very loud with useful bass and long claimed battery life, making it a credible choice for outdoor gatherings. Watch for: At high volume, reviews report distortion and fluctuating level, so its headline power is more useful below its maximum setting. It has no app-based EQ, and the bass and midrange refinement do not match better-established boombox speakers; assess its sound in person if tonal accuracy matters.
Buy the Diamondboxx M3 when sound quality outweighs the price for you, and the Zealot S78 when the price outweighs sound quality instead.
The Zealot S78 is not a sound-quality pick. It sits near the bottom of the 75 boombox speakers; there are better options higher up.
There is a real gap in water resistance: the Zealot S78 at IP67 (brief submersion) against the Diamondboxx M3, which has no water resistance.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Diamondboxx M3 | Zealot S78 | |
|---|---|---|
| Price | $700 | $159.68 |
| Ranked | #53 of 75 in Boombox Size Portable Bluetooth Speakers | #75 of 75 in Boombox Size Portable Bluetooth Speakers |
| 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 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 |
Related Speaker Comparisons
How Diamondboxx M3 compares with other leading options:
- Tribit Stormbox Blast vs Diamondboxx M3
- JBL Partybox Encore 2 vs Diamondboxx M3
- JBL Partybox Encore Essential 2 vs Diamondboxx M3
- Diamondboxx M3 vs JBL Partybox Encore
- JBL Partybox Encore Essential vs Diamondboxx M3
Prices on this page were last checked September 16, 2026 at 12:41 AM 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
Diamondboxx M3: $700 eBay
Pros: An unusually compact 5kg high-output boombox, with a claimed 200W RMS Class A/B amplifier, 114dB maximum level, active crossovers and a choice of large battery packs. It has aux input, USB-C power and TWS pairing, while the aluminum heat sink is designed to sustain loud playback without thermal shutdown.
Cons: Despite its output, bass does not reach as deep as the best large portables and can distort when pushed hard. The treble-forward tuning can sound aggressive, there is no app or EQ to correct it, and the lack of a water rating makes it a poor match for poolside or rough-weather use.
Full Diamondboxx M3 review and specifications →
| Amplifier Power | 200W RMS / 400W peak |
|---|---|
| App | No |
| Aux Input | Yes |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 14.7" x 9" x 8" (373.4 x 228.6 x 203.2 mm) |
| Drivers | 3" woofer + tweeter array |
| EQ | No |
| FM Tuner | No |
| IP Rating | None |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | No |
| Weight | 11 lbs (5 kg) |
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons
- Diamondboxx M3 vs W-King D10
- Diamondboxx M3 vs Demerbox DB2
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- Diamondboxx M3 vs EcoXGear Defender
- Diamondboxx M3 vs JBL Partybox On the Go
- Diamondboxx M3 vs Onn Medium Party Speaker Gen 2
- Diamondboxx M3 vs Marshall Tufton
- See all 44 comparisons
Zealot S78: $159.68 Amazon Aliexpress eBay
Pros: A robust 4.4kg party speaker with claimed 120W RMS output, IP67 protection, USB-C charging, a power-bank function, aux, USB and microSD playback, TWS pairing and multiple EQ modes. Reviews find it very loud with useful bass and long claimed battery life, making it a credible choice for outdoor gatherings.
Cons: At high volume, reviews report distortion and fluctuating level, so its headline power is more useful below its maximum setting. It has no app-based EQ, and the bass and midrange refinement do not match better-established boombox speakers; assess its sound in person if tonal accuracy matters.
Full Zealot S78 review and specifications →
| Amplifier Power | 120W RMS / 150W peak |
|---|---|
| App | No |
| Aux Input | Yes |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.1" x 6.6" x 7.3" (410 x 167 x 185 mm) |
| Drivers | 2x ~120mm (4.72") woofers + 2x ~42mm tweeters + 2x passive radiators |
| EQ | Yes (multiple modes) |
| IP Rating | IP67 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | Yes (USB-A) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 9.7 lbs (4.4 kg) |
- Reviews, Comparisons and Sound Samples
- Jay’s Straight Up Reviews & More: W-King X20 vs Zealot S78 Bluetooth Boombox Battle Outdoor Tailgater Special 🚗 Let the Whoopin’ Begin More from JaysStraightUpReviews →
- Jay’s Straight Up Reviews & More: DBSOARS F29 Max vs Zealot S78 🛜 (5B) Budget Bluetooth Boombox Basement Battle 🔊 Bass Modes Enabled
- Head-to-Head Comparisons