noun
resonance box; sound box
A hollow chamber that amplifies sound through resonance, as in a musical instrument or speaker enclosure.
バイオリンの共鳴箱が豊かな音を生み出す。
The violin's resonance box produces a rich sound.
共鳴 means 'resonance' or 'sympathy'; 共鳴箱 is the physical box that creates resonance.
Compound of 共鳴 (resonance) + 箱 (box).