Extensive connectivity options Designed for versatility, this Subwoofer Amplifier Board provides multiple input options to fit a wide range of devices. It supports BT (Bluetooth), a 3.5 mm AUX input, and 3 PIN inputs, ensuring compatibility with almost any home audio source such as mobile phones, tablets, computers, and CD players. This gives you flexible, effortless integration with your existing audio gear. Easy control interface The ZK TB21 power amplifier board offers precise sound with an intuitive control layout. It includes: Subwoofer volume control for easy bass adjustment Independent treble and bass controls for the left and right channels Inbuilt subwoofer low pass filter and crossover control for detailed, tonal shaping of the output Together, these features let you tailor the listening experience to your room and preferences without complexity. Powerful output capability Delivering a strong 2.1 channel setup, this board provides 50 Watts x 2 for the left and right channels and a 100 Watt subwoofer channel. It operates from a DC supply of 12 to 24V and is compatible with passive speakers rated 4 to 8 ohms and 50W to 300W. This combination offers robust sound performance with clear bass emphasis and responsive highs, suitable for a range of home audio configurations. Clear and simple layout Engineered for simplicity and reliability, the 2.1 channel amplifier board features a clean, compact layout that minimizes popping and audible noise, even at higher power levels. This helps ensure a smooth, uninterrupted listening experience and makes integration into your existing setup straightforward. 23 practical use scenarios Home entertainment upgrade: Use the BT, AUX, or 3 PIN inputs to connect a TV, computer, or CD player. The independent tone controls and subwoofer crossover let you balance dialogue, music, and bass for a more immersive viewing experience without distortion. DIY speaker project: Pair the board with passive 48 ohm speakers and a suitable enclosure to build a compact 2.1 system. The 50W x 2 mains and 100W sub channel provide ample driving power for casual listening or small rooms, with flexible tone shaping to suit your cabinet and room acoustics. Small home theater or music room setup: Create a focused listening environment by using the 2.1 channel arrangement to emphasize cinematic bass and clear highs. The builtin filters and crossovers help maintain clean response across genres and movie soundtracks.