First, turn on the amplifier's switch, try to maximize the sound, listen to whether there is noise. If there is no noise, it means there is no noise in the amplifier when it is working. Some poor quality loudspeakers are very prone to noises at this time. Such loudspeakers are not worth buying. It won't take long.
Second, use loudspeakers to amplify the sound when the sound of the loudspeaker is maximized. Listen carefully to see if the amplified sound is distorted. If the loudspeaker is loudest, the sound quality is clear and the sound is loud enough. Most of these loudspeakers are not poor loudspeakers.
Third, although the appearance of loudspeakers is not the most important factor in the work of loudspeakers, the workmanship of loudspeakers is indeed a factor worthy of careful study. If the work of loudspeakers is very rough, most of these loudspeakers are immature. The probability of a quality problem is also high for the product.
Fourth, does the function of the loudspeaker meet the requirements, whether it supports U disk, TF card, FM radio, one-key circulation function, etc.