AES Fall Convention 2023

As critical listening rooms have evolved from monophonic, stereo, and surround to the present fully immersive designs, many approaches have been taken in the design of recording control rooms. The importance of the neutrality and transferability of these room is essential, because it is well understood that if you can’t take the room out of the mix, you can’t take the mix out of the room. This presentation will review significant milestones in this evolution over the past 4 decades of my career in acoustics. It will include the importance of measurement technology, beginning with time delay spectrometry; novel acoustical material product development and measurementstandards, including reflection phase grating diffusers and dedicated low frequency modal absorbers; as well as the creation of the reflection free zone/diffuse field zone control room design, which is currently adopted as a de facto standard in many current projects. In addition, the role of design software will be discussed from the original cuboid image model room optimization programs to a current full bandwidth hybrid program, which combines a wave based FEM modal model and a geometrical acoustic model above the Schroeder frequency, to simultaneously optimize the geometrical design of any shaped room, the location of speakers and listeners, as well as the acoustical treatment. The result is a full bandwidth impulse response which can be used to auralize the room. Many examples of milestone projects will be presented, accompanied by a discussion of my scientific collaborations with the recording studio designers associated with each project.