I recently upgraded my cassette player by replacing the original MP3 input, and I noticed a significant improvement in sound quality. However, I felt that the bass was lacking. To enhance the low-end, I added a 5-inch active subwoofer, which I placed under the co-pilot seat. It cost around 80 yuan for two high notes, but it made a big difference. I connected the input from the PT2313's output pins 24 and 25 (though the datasheet mentions outputs 22 and 23 or 24 and 25, I chose 24 and 25 because they are easier to wire). This setup allows me to control the volume directly from the panel, resulting in a much better listening experience with a more powerful and immersive sound. The effect is truly impressive.
Additionally, the radio signal is also routed through these same outputs, making this setup versatile for both music and radio. If you're a fan of deep bass, this could be a great option for you. Below is the circuit diagram of the PT2313 for reference.
Shanghai Janetec Electric Co., Ltd. , https://www.janetecelectric.com