There is always noise in the high-pitched part of erhu. How to solve it?

The essential reason is that erhu, whose quality is not particularly high, will be very noisy when it reaches a high position, commonly known as "wolf sound". However, there are ways to control it. First, the sound pad of the erhu has been adjusted, that is, the erhu comes with one or two pieces called sound filter pads when it leaves the factory. Generally, wool felt or thick woolen cloth is cut into two or three inches square pieces, which are folded and sandwiched between the lower chord and the leather. The tightness can be adjusted by audition, and it can be looser at first. If there is a wolf's voice, it can be thickened appropriately until the noise is very small, and it can be adjusted by moving up and down. If not, you can also use high-quality sponge or foam instead, but the effect will be worse. Furthermore: 1. The quality of erhu is not good, and the timbre is not so excellent. 2. The technique is not good, and it is not allowed. 3. The inner and outer strings of a thousand catties are mixed together. The piano and horse in snakeskin bar are not ready yet. That's about it.