A loud hiss is coming from the audio system.

A loud hiss in an audio system is most commonly caused by poor gain structure. Gain structure refers to the optimal setting of input and output levels throughout an audio system to minimize noise and distortion while maximizing signal quality. Incorrectly set gain levels can amplify the inherent noise floor of the system, leading to audible hiss. Ensuring proper gain staging at each step—from microphones to mixers to amplifiers—helps reduce this noise.