The level of the tone 5 (Sol) can be completely done by the repair of the reed. Under normal circumstances, the drum tone will have a process from high to low, but the length of time is different.

The low bass 5 (Sol) is caused by the excessive wear of the base of the reed tongue. If you find this situation, you need to remove the head of the instrument first (be careful not to damage the reed when removing it), and check whether the bamboo stick is tight. Press the reed, if it is loose, reset the bamboo stick to the position close to the reed frame, and then try to play the scale, the tone of the drum should be raised (if there is no bamboo stick, skip this step). If the bass 5 (Sol) is still low, you need to prepare a small sharp knife, sharpen the tip, and also need a metal gasket (with a certain hardness, the thickness is similar to the paper cutting blade, and the length and width should exceed the reed tongue), A half-cut paper blade can also be used instead. First, remove the bamboo stick that presses the reed, and gently insert the metal washer between the reed and the reed frame from the raised part of the reed tongue, and maintain the original tilting angle of the reed tongue (the action should be light, slow, And it should be slowly inserted along the cocked angle of the spring tongue to a place about 4-5mm away from the root of the spring tongue. If the tilt angle of the spring tongue changes, it should be reset after the repair of the spring tongue is completed), and then use a small knife Lightly scrape the tongue tip of the spring at a vertical angle for two to three times, a little metal powder will be scraped off (depending on the sharpness of the knife tip). The sign should press the reed tightly), try blowing it, the bass 5 (Sol) of the reed will slightly increase, if it is not enough, repeat the scraping two or three times until the bass 5 (Sol) returns to the normal pitch. If you accidentally make the bass 5 (Sol) too high and affect the overall interval relationship, then you have to use the same method to lightly scratch the 2-3mm of the base of the reed tongue, and the bass 5 (Sol) will be lowered. After the debugging is accurate, install the main pipe, fix the main pipe and the auxiliary pipe, glue and seal it with latex, and use it after the glue is completely dry.

If the tone of the barrel is too low (over 50 cents), it is difficult to repair the reed with the above method. Even if it is repaired, the sound of the reed will not be very good. It is best to replace the reed with a new one.