这个扬声器内置了一个铜制谐振器来增强音质。

The speaker has a built-in copper ___resonator to enhance the sound quality.

小提琴的共鸣箱增强了琴弦的振动，使声音更加饱满。

The violin's ___resonator amplifies the strings' vibrations to produce a richer sound.

这个金属管被用作音频系统的谐振器。

The metal tube acts as a ___resonator in the audio system.