When a microphone signal first enters a mixer, which of the following is used to control the input level of the audio?

The component used to control the input level of the microphone signal as it first enters a mixer is the gain control. Gain is crucial in the audio mixing process because it adjusts the level of the microphone's signal before it is sent to other components or processes within the mixer or audio system.

By increasing the gain, the audio signal from the microphone is boosted to a suitable level for processing, ensuring that it is strong enough to be effectively mixed with other audio sources. This is particularly important because it helps prevent noise and ensures clarity in the sound.

While faders are used to adjust the output level of a channel after the signal has been processed, and equalizers modify the tonal balance of the signal, gain specifically addresses the initial input level. Compressors, on the other hand, manage the dynamic range of audio but do not set the initial input level. Understanding the distinct roles of these components within the mixing process is essential for achieving optimal audio quality.