Only when the audio input is sufficient and the supply voltage/current is sufficient will there be enough output . If the supply voltage is higher, the relative will be higher. Speakers with different impedances will have different output powers. In the case of sufficient voltage and current, the larger the ohms of the speaker, the smaller the relative sound , please pay attention! voltage: 12V ------- 8 ohm speakers/12W (left channel) + 12W (right channel) 4 ohm speakers/20 (left channel) + 20W (left channel), 15V ------- 8 ohms/18+18W, 4 ohms/greater than 30+30W, 19V ------- 8 ohms/32+32W, 4 ohms/greater than 45+45W, 24V ------- 8 ohms/38+38W, 4 ohms/greater than 55+55W, Product name: 2.1 channel audio amplifier board Supply voltage: DC12-24V Output : 50w*2+100w subwoofer*1 Output load: 4-8ohm Frequency response range: 14-100KHZ Number of channels: 3 (left channel + right channel + subwoofer) Switching frequency: 1.2MHZ Colour:orange Material: PCB Size:100 x 70 x 30mm Package Contents: 1 x digital amplifier board Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.