A soundboard optimally transfers vibration without being too resonant itself

Evidence

The soundboard is the perfect intermediary between the strings and air. It does not need to become resonant, or better impedance matched to the strings, or more efficient, lest it sap the vibrations of the strings too quickly, or favor one string over another. — Eric J. Heller, Why You Hear What You Hear- An…, 1182

Categorization

• DEFINE: Explains the ideal role of an intermediary structure like a piano soundboard: neither too resonant nor too efficient, so all strings radiate equally.