AES San Francisco 2010
Master Class M2
Thursday, November 4, 2:30 pm — 4:30 pm (Room 206)
M2 - High Resolution Computer Audio
Keith O. Johnson
Computers, televisions, and mobile devices are functionally merging and integrating to become easy to set up fun to run systems. Right now, server-like versions can play high-resolution multichannel files from workstations, function as a control center, create loudspeaker crossovers and equalization, as well as perform room correction using all loudspeakers. Data management and processing create these advanced features but systems like these can present issues with processing activity, sample rate conversion, jitter, noise propagation, digital conversion, and interfaces. One encounters discussion about perceptual differences from technical changes that should not affect accuracy nor produce large differences in timing spectra. The class will briefly introduce systems and components, then show potential behavioral artifacts within system parts and describe test methods that might reveal explanations. Then we'll explore process monitoring, buffers, quick locking low jitter clocks, floating conversion environments, jitter from OP Amps and a test methodology that targets process related intrinsic behavioral problems. Cluster, subtraction and DSP overload tests will be described along with projected human perceptual and mental load that might have audibility or hinder playback involvement. This presentation of an overall background knowledge should encourage studies that are more detailed and it should be helpful with creation and development of very high quality systems.