Phonic PAA6 Manual Del Usuario página 26

Compare Function (Subtract/Sum): Users can also opt to add the results from channel 1 to those of
channel 2 together, or subtract either channel from the other (to compare the difference in level). This
option is set up in the SET menu, and is activated by pushing the appropriate onscreen icon (CH1+CH2,
CH1-CH2 or CH2-CH1). See figure 32.
figure 32
PAA6
22