In the era of acoustic recordings, the first recording studios were simple soundproof studios that isolated the internal environment from the external one. The recordings are made in an analogue way, musicians were grouped around an acoustic horn, a sort of large phonograph. The acoustic energy of the voices and/or instruments was channeled through the diaphragm to a mechanical cutting lathe located in the adjacent room, which directly cut the signal as a modulated groove, directly onto the disco surface. After the commercial introduction of the microphone, electric amplifier, mixing desk and loudspeakers, the recording industry has gradually transformed.