But if the goal is to reproduce sounds accurately, then a speaker must be either an acoustic point source (monopole, omni-directional) or an acoustically small bi-directional source (dipole).

但是，如果目标是精确的重放声音的话，一个扬声器必须是声学上的点声源(单极点，全向响应)，或者是一个声学上小的双向源(偶极)。

youdao

But if the goal is to reproduce sounds accurately, then a speaker must be either an acoustic point source (monopole, omni-directional) or an acoustically small bi-directional source (dipole).

但是，如果目标是精确的重放声音的话，一个扬声器必须是声学上的点声源(单极点，全向响应)，或者是一个声学上小的双向源(偶极)。

youdao