In music:
* Electric: This refers to instruments that use electronic amplification, like electric guitars and basses.
* Electronic: This refers to music created using electronic instruments and software.
In sound engineering:
* Electronic: This refers to sound reproduction or amplification using electronic devices.
* Digital: This refers to sound recorded and manipulated digitally.
In general usage:
* Amplified: This means using electronics to increase the volume of sound.
* Artificial: This means not naturally produced.
Therefore, the best opposite of "acoustic" depends on the specific context and what you are referring to.