Short answer: the X20, and the ranking gap is enormous. It ranks #43 of 113 boombox speakers at $229.99; the S78 ranks #111 at $91.38, $138.61 less and near the very bottom of the class.
The S78’s spec sheet reads well: 120W RMS output, a 40-hour battery, a power bank function, and IP67 waterproofing. Our notes describe real problems in practice: it gets distorted above 50% volume, doesn’t have much bass, and its volume level fluctuates at high output.
The X20 answers with a 7.5-inch subwoofer and 330W peak power, with its own cons limited to a rising frequency response and peaks at 700Hz and 1.2kHz, modest by comparison.
Buy the X20. The $138.61 premium buys a speaker that actually works reliably at volume.
There is a real battery-life gap here: the Zealot S78 is rated for 40 hours, the W-King X20 only 24 hours.
Want more options? Browse the full Portable Bluetooth rankings.
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Specifications Side By Side
| W-King X20 | Zealot S78 | |
|---|---|---|
| Price | $229.99 after coupon | $91.38 |
| Ranked | #43 of 113 in Boombox Size Portable Bluetooth Speakers | #111 of 113 in Boombox Size Portable Bluetooth Speakers |
| App | Yes (W-King app) | No |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | ~42Hz | - |
| EQ | Yes (App + button modes) | Yes (multiple modes) |
| IP Rating | IPX6 | IP67 |
| Maximum SPL | 112dB (measured by Alan Ross Reviews) | - |
| MicroSD Playback | Yes | Yes |
| Power Bank | Yes (USB-A) | Yes (USB-A) |
| Power Input | USB-C | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | Yes |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Party Mode | No | No |
| Built-in Microphone | No | No |
| Amplifier Power | 330W peak / 200W RMS | 120W RMS / 150W peak |
| Dimensions | 19.9” x 8.5” x 10.6” (506 x 217 x 270 mm) | 16.1” x 6.6” x 7.3” (410 x 167 x 185 mm) |
| Drivers | 7.5” subwoofer + drivers | 2x ~120mm (4.72”) woofers + 2x ~42mm tweeters + 2x passive radiators |
| Weight | 15.9 lbs (7200 g) | 9.7 lbs (4.4 kg) |
| Digital Aux Input | No | No |
| Battery Life | 24 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| Bluetooth Version | 5.4 | 5.3 |
| Strap | - | Yes (detachable shoulder strap) |
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