Resonance peaks are always balanced by anti-resonant valleys nearby

Evidence

Suppose we have a body that extends to infinity and returns no echoes. The power as a function of frequency will be smooth, and forms a reference level. If echoes and resonances are induced by adding structures and boundaries some distance away, resonances will develop, enhancing the power at certain frequencies. The average power theorem dictates that resonance peaks must rob Peter to pay Paul; resonance peaks must be compensated by nearby dips where the power is lower—that is, anti-resonant valleys. The power averaged over large enough frequency intervals must equal the power that would be delivered if the echoes and their resonances didn’t exist. — Eric J. Heller, Why You Hear What You Hear- An
, 1092

Categorization

Category: Causal Relationships

  • SEED: The ‘rob Peter to pay Paul’ conservation picture — resonance enhancement inevitably costs sensitivity elsewhere — is a ready-made article angle on what resonances really do.
  • CANDY: Resonance peaks are fiscally conservative: they rob Peter to pay Paul, balanced by compensating dips.