20"

B A 71 dB

D A 74 dB

C B 71 dB

D C 70 dB

D C 73 dB

C A 71 dB

C B 73 dB

C A 73 dB

D C 70 dB

B A 70 dB

B D 70 dB

D A 70 dB

D A 73 dB

D A 73 dB

D B 71 dB

C B 71 dB

B C 70 dB

C C 72 dB

C A 74 dB

D A 72 dB

C C 72 dB

B B 71 dB

A B 72 dB