What is RT-60 and how is it important to design a Music room & Home theater room? A: RT-60 is a measure of the reverb time of the residual sound once the source of the sound has stopped. It is a measure of the time it takes for the sound to bounce back with a 60dB drop in sound level when the source stops. These numbers can indicate the personality of the place or room in which we are measuring. Whether that room has a Dead sound or Live sound. Both of which depend on the design of the room that is different. PS: Article content will be gradually added according to each topic.