HAMPPEP B13 - Acoustic parameters

HAMPPEP DLα absorbence capacity        DLR sound transmission loss by air 
B13/O                                         -  B3-28 dB            
B13/JP             A3-8 dB, A4-from15 to 20 dB (2 variants)                   B3-from 29 to 30 dB            
 B13/OP A3-8dB, A4-from 15 to 20 dB (2 variants) B3-from 29 to 30 dB