Destructive Interference

When two wave signals S1 and S2 have the same frequency and same amplitude, but are 180o out of phase, the net effect is a signal (S1+ S2) that has no amplitude at all -- the signals cancel out.

Notes:

When two wave signals S1 and S2 have the same frequency and same amplitude, but are 180o out of phase, the net effect is a signal (S1+ S2) that has no amplitude at all -- the signals cancel out.