Clients have questioned the new names for home theater systems such as 5.1.2 or 7.2.2, or 7.1.4 and are wondering what does the 3rd number mean. To quickly recap, the 1st number is the number of speakers and the 2nd number is the number of sub-woofers. In a typical 5.1 system, there are 5 speakers, front left and right, center, right rear and left rear along with a single sub-woofer. In a 7.2 system, 2 side speakers are added along with a 2nd sub-woofer. But what about the 3rd number? This number represents the number of vertical speakers used in Dolby Atmos sound to create a 3D sound field. These speakers can be located in the ceiling or in the front of the room placed directed towards the ceiling. You can add multiple vertical speakers to any Dolby Atmos certified receiver since the Dolby Atmos format treats sound as objects rather than a traditional audio channel. You may already have experienced 3D sound at your favorite movie theater. To have Dolby 3D Atmos in your home theater, 2 things are necessary, a certified Dolby Atmos system and Dolby Atmos content. Many Blu-Ray DVD and steaming video services offer Dolby Atmos programs.