1) the output sound quality is closely related to the input level and output level. Normally, the input level is less than -20db and the output level is less than -15db. At this point, adjusting other parameters will have a better effect.
2) Check whether the configuration of other parameters, such as EQ parameters and frequency divider are reasonable.
3) The signal generator will produce some noise, check whether it is turned off.
4) The noise door can filter the white noise when there is no human voice, open the noise door and then detect the sound quality.
5) The echo will be generated when the mic is input, which can improve the sound quality by turning on feedback elimination.