Dolby does not define specific acoustic standards or requirements for Dolby Atmos mix rooms. Studio acoustics are well covered by established design literature and international standards such as ITU-R BS-1116-1. However, when designing a Dolby Atmos mix room, the following acoustic considerations may help achieve accurate monitoring performance.

Room Modes 

Room modes cause certain frequencies to vary in level throughout a space, creating areas where sound may be perceived as excessively loud, boomy, or resonant, and others where it may seem weak, thin, or lacking in energy. These variations are the result of acoustic resonances determined by the room’s dimensions and boundary conditions, with the most significant effects occurring at low frequencies.  

When possible, the impact of room modes can be minimized during the design phase by selecting room dimensions and proportions that promote a more even distribution of modal frequencies across the spectrum. This helps reduce the concentration of resonances at specific frequencies and improves overall response.  

The Dolby Atmos Room Design Tool HE+Music includes an Acoustic Analysis sheet (available in Advanced and Music Advanced modes) that provides basic room ratio analysis and can be used to predict the frequencies at which theoretical room modes may occur. Several online room mode calculators are also available and can be used to further evaluate modal behavior within a proposed room design.   

The effects of room modes can also be mitigated by placing speakers near walls as opposed to in the center of the room, deploying bass traps in room corners, and/or experimenting with the location of the mix position. 

Early Reflections and Reverberation 

Early reflections, also known as first reflections, are sound waves that bounce off a single surface before reaching the listener's ears. These reflections carry substantial energy and can influence the perceived timbre, clarity, and spatial characteristics of the sound. A common guideline is to ensure all early reflections are at least 10 dB lower than the direct sound from the speaker. In addition to addressing early reflections, it is strongly recommended to manage overall room reverberation to ensure optimal acoustic performance. Excessive reverberation can distort the perception of the mix, while too little can strip away realism. The goal is to find a balance between retaining enough reverberation to preserve the sense of space, while still allowing for accurate creative choices. 

Dolby does not prescribe specific RT60 targets for Dolby Atmos mix rooms. Ideal RT60 values vary depending on the size of the room and can be guided by established literature and standards. The Dolby Atmos Room Design Tool (DARDT) includes an RT60 analysis section which displays industry guideline RT figures relative to room volume.   

To effectively manage both early reflections and reverberation, incorporating a combination of sound-absorbing panels and diffusers is recommended. While consulting a professional acoustician is ideal for optimal results, a general starting point is to aim for a balance of approximately 60% absorptive surfaces and 40% reflective or diffusive elements. 

Because every room is unique, it is recommended to consult a professional acoustician or studio designer who can evaluate the acoustic performance and suggest appropriate treatments.  

To hear from others who have set up their studio, join the Dolby Creators Community on Discord.