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This widget plays two identical signals through two paths and lets you delay or invert one. The most dramatic moment: identical signals + polarity flip = silence. Headphones recommended.
Foundation · Module 2.5 · How You Hear
Phase & Polarity
Why two identical signals can become silence — or hollow comb filtering — depending on how they meet.
Two identical signals, perfectly aligned
Press Play. Both paths are identical 1 kHz sine waves with no delay, no polarity flip — they reinforce each other. The combined output is exactly twice as loud as one path alone (+6 dB). Now click Flip Path B polarity — the two waves cancel completely. Silence. That's the polarity flip in its purest form. The two waves are physically opposite, and they sum to zero everywhere.