IS2801-4 is a part of Isocom, a series of active noise control systems designed to reduce background noise in various industrial, commercial, and residential applications. Isocom consists of five different parts, which cover a range of noise sources. The IS2801-4 is a combination of two active noise control systems, one for low-frequency noise and one for broadband noise. This system is designed to reduce the noise created by fans, compressors, and other industrial machines. The system includes an input device which captures the audio noise, a signal processor which filters noises, and an output device which injects the counteracting noise to reduce the existing noise.