ZK-TB21 TPA3116D2 Bluetooth 5.0 Subwoofer Amplifier Board 50WX2+100W 2.1 Channel Power Audio Stereo

Feature: 1.How to choose the power supply? The power supply with the board is very key, the selected power supply ripple must be small, ripple large power supply will lead to power amplifier bottom noise, there is a current sound.The higher the voltage, the higher the current, and the higher the power output. If you only have 12V 1A, you can have 3-4 inch speakers.If you are above 19V 5A, no problem with 8-10 inches, power must be highly valued.If the voltage is too low and the sound is amplified, it will easily cause sound distortion. If the current is too low and the horn cannot be brought up, the voltage will be pulled down, which will lead to abnormal operation or poor sound quality. It is recommended to use 18V19V24V power supply with current above 5A.If you only have 9V12V or 1A 2A power supply, you can also use it but with low power. When using it, choose the volume close to the maximum, which may cause distortion and affect the sound quality. 2.How to select speakers? About the speaker type: commonly used speakers are generally 4-8 ohms, can be used.Speakers in left and right channels need to be connected to full frequency or medium and high frequency speakers with power between 20W and 100W.Subwoofer speakers cannot be connected to ordinary speakers. Speakers with subwoofer speakers should be connected, with power between 20-100W.The subwoofer horn must have a dive frequency of at least 50Hz. If your speaker power is small, such as between 20W-50W can also be used, the power supply voltage needs to be small, to prevent the loudspeaker burnt after loud, such as choose power below 15V.If you are a 50W-100W speaker, you don't have to worry about burning out the horn. You can choose a 12-24V power supply. The higher the voltage you choose, the more sound or power you can output.Speaker power is not easy to exceed 100W, otherwise it will affect the sound quality. 3.Audio input mode: There are two audio input modes for this audio amplifier module: one is Bluetooth input and the other is AUX input. Bluetooth mode is preferred.Bluetooth can be connected in either mode.As long as the Bluetooth connection is successful, it is bluetooth mode, and bluetooth mode supports automatic back up.AUX insert is AUX mode when Bluetooth is disconnected.It should be noted that the bluetooth connection of this module is disconnected when using AUX mode. 4.How to adjust the main volume? The MAIN - VOLUME knob is used to adjust the MAIN VOLUME.The right main volume goes up and the left main volume goes down.The master volume affects both the left and right channels and the subwoofer volume. 5.How to adjust the height and bass of the left and right channels? R&L CHANNEL - BASS knob is for BASS, right-handed BASS enhancement, and left-handed BASS attenuation.When the knob is in the right-most position, it does not enhance or attenuate the bass. The R&L CHANNEL - TREBLE knob is used to control the TREBLE, with right-handed TREBLE enhan