ZK-502MT Subwoofer AUX Digital Audio Power Amplifier Module Board Features:

Name: 2*50W Blue tooth audio amplifier module with sound
Blue tooth version: 5.0
Methodology Inputs: AUX + Blue tooth
Channels: 2
Adapter power supply: above DC9-24V/3A
Compatible speakers: 10-100W, 4-8 ohms
Colour: Black
Dimensions: 89x60x21mm / 3.5x2.36*0.83"

Package Contents:

1 x Blue tooth Audio Amplifier Modules (the case needs to be assembled)
You need to prepare 12/24V power adapter by yourself.

Tip: Only when there is sufficient audio input and sufficient power supply voltage/current, will there be sufficient output power! The higher the power supply voltage, the greater the output power, and the smaller the speaker impedance, the greater the output power! Please ensure that the power of the adapted power supply is greater than the actual working power of the amplifier!!! 

Warmly Notes:
Due to the light and screen difference, the item's color may be slightly different from the pictures.
Please allow a slight deviation for the measurement data and make sure you do not mind before ordering.

FAQs:
1. How to choose a power supply?

Re: The power supply that matches the module is critical. The power supply requires small output ripple and low internal resistance. The higher the voltage, the greater the current, and the greater the output power. If you only have 12V2A, you can use 3-4 inch speakers. If you have 19V5A or more, it is no problem to use 8-10 inches. The power supply must be highly valued. If the voltage is too low, the sound will be easily distorted after amplification. If the current is too small to drive the speaker, it will pull down the voltage, malfunction or poor sound quality.

It is recommended to use a 18V19V24V power supply with a current of more than 3A. If you only have a 9V12V or 1A 2A power supply, you can also use it, but the power is small. Please note that when using it, turning the volume to the maximum may cause

Distortion affects the sound quality.

2. How to choose a speaker?

Re: Commonly used speakers are generally 4 ohms or 8 ohms. If your speaker has low power, it may be between 20W-50W and can be used. The power supply voltage should be lower to prevent the speaker from burning out after amplification, such as choosing a power supply below 15V. If you have a 50W-200W speaker, don't worry about the speaker burning out. You can choose a 12-24V power supply. The higher the voltage, the greater the sound or power that can be output. The speaker power should not exceed 100W, otherwise it will affect the sound quality.

3. How to select the audio input mode?

Re: This audio amplifier module follows the principle of hardware priority. If the USB connection is successful, it is USB mode.

If AUX is plugged in, it is AUX mode. If USB is not connected and AUX is not plugged in, it is Bluetooth mode, which supports automatic reconnection. There is a mode prompt sound when the mode is switched. When selecting USB audio input mode, it should be noted that USB can be directly connected to a computer or other device with USB audio output (no driver installation is required), or it can be directly inserted into a U disk for use. USB input is lossless input, with good sound quality, no interference, and no noise.

4. It's fine when the sound is low, but when it gets louder, the sound becomes muddy?

Re: The sound is distorted. Please change to an adapter with a higher voltage level.

5. It's fine when the volume is low, but when it gets louder, the sound freezes?

Re: The input power is insufficient, and the power supply itself is intermittently powered off for protection. Please replace it with a power supply with a higher power. Or the power is too high, the amplifier board is seriously overheated, and thermal protection occurs. Reduce the power usage or increase the heat dissipation.

ZK-502MT Subwoofer AUX Digital Audio Power Amplifier Module Board Pictures:

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