If the speaker needs more current (its overall impedance drops) then a lower amplifier output impedance will allow that current to be drawn out of the amplifier without causing much of a change in the applied voltage - and that means less distortion.
If the speaker needs more current (its overall impedance drops) then a lower amplifier output impedance will allow that current to be drawn out of the amplifier without causing much of a change in the applied voltage - and that means less distortion.
如果扬声器需要更大电流（扬声器的整体阻抗降低），那么一个低输出阻抗的放大器可以容许在输出相应电流的同时，所施加的电压变化更小，这也意味着失真更小。