Normal phenomenon. According to relevant public information, it is normal for Alpine amplifiers to be very hot. Generally, the temperature of the amplifier will increase if it is used for a long time. However, the amplifier can be used normally as long as the temperature is lower than 80 degrees. Car disc boxes are commonly known as car-specific MP3, car MP3 disc boxes, and car music boxes. After the technology of multi-disc boxes was gradually digitized, a standard digital disc box developed specifically for the CD interface of the original car appeared.