Brickwalled
Brickwalled is a term used in audio engineering and music production to describe a phenomenon that occurs when a digital audio signal is amplified to its maximum possible level, causing a distortion known as clipping. This happens when the audio signal exceeds the maximum amplitude that can be represented by the digital system. Instead of smoothly exceeding the limit, the waveform is abruptly cut off at the peak, creating a flat, square-like shape. This results in a loss of dynamic range and introduces harsh, unpleasant harmonics. The term "brickwalled" is a metaphor for the signal being unable to pass a solid "wall" at its maximum level.
This effect can happen intentionally or unintentionally during the mixing and mastering stages of audio production.