The highlight of the Mifa A20 Bluetooth 4.2 speaker is the true wireless stereo (TWS) function that lets you play music wirelessly via two A20 speakers simultaneously. This means you can pair a second A20 speaker and enjoy stereo sound.
The Mifa A20 TWS function works similarly to that of a pair of true wireless earbuds as you pair one speaker to your device while the second speaker connects to the first speaker.


As you can pair the Mifa A20 speaker to multiple devices, you can disconnect the A20 speaker from a current device to pair it with another device (you can manually pair back to the last paired device by simply "short pressing" the Bluetooth button). The A20 will automatically connect to the last paired device too.
Internally, the Mifa A20 speaker features two front-facing 43mm speaker drivers driven by a built-in amplifier in the back of the unit and two passive radiators (bass radiators) on the back of the unit that increase the bass frequency. The total RMS output is 30W which is pretty decent for a speaker of this size.
Compared to a similar speaker without passive radiators, the A20 sounds a lot more boomy, which it would because of the passive radiators which work very much like a ported speaker box in a subwoofer speaker system.
It's neat that the A20 speaker is fitted with bass radiator technology because it is a simple, yet effective way to increase the bass on a small speaker.
The user control buttons on the Mifa A20 are located on top of the unit. From left to right they include mic, volume(-), bluetooth, power, play/pause, volume(+) and battery led indicator.
The volume (-) lets you play the previous song (press and hold) and volume down (short press), while volume (+) lets you play the next song (press and hold) and volume up (short press).
The power button doubles as the power on/off button (long press) and switch mode button (short press) to toggle between wired mode, wireless mode (Bluetooth 4.2) and micro SD card mode, which automatically plays the music stored in the micro SD card after two beeps (supports up to 32GB size cards).
You can manage music files in the micro SD card from a computer by connecting the charging/data micro USB cable included and holding down the power button for two seconds to turn on data transmission.
When data transmission is turned off, charging mode kicks in automatically. To fully charge the 4000mAh built-in lithium-ion battery it takes 4.5 hours but you get around half a day of play time.
Wired mode is automatically entered when inserting the 3.5mm audio cable (you will hear one beep). The play/pause button also doubles as the button to answer, end and reject phone calls

The led indicator on the Mifa A20 30W speaker consists of three small leds that indicate battery charge. When the three small leds show solid white, it means full charge (100%). Two solid white leds indicate 75% charge remaining. One solid white led indicates 30% charge remaining (this led turns solid red when the battery is low and starts flashing red when battery is almost depleted).