We work closely with the Donghai Station of the Institute of Acoustics, and we can use the cylindrical wave tube method in our internal laboratory to find and distinguish the sound absorption performance of different materials in different frequency bands, and apply them to corresponding engineering cases. The selected materials also meet DIN4102, national standard GB8624-2012 B1 non-flammable standard or flame retardant A1 standard. Now we have built more than 300 engineering cases across the country using new polymer foam materials, and users have highly praised its sound absorption advantages. At the same time, through our painstaking research, we have designed a flat plate resonance sound absorption technology that is different from traditional wedges. , it can use limited space to achieve low cut-off frequency acoustic performance, the lowest can reach 50Hz.