ELE 791 Real World Signal Processing Spring 2005 Syracuse University 22 Feb 2005

ELE 791 :: Outline [22 Feb 2005] n Assignments n Simple System Design Tasks n Digital Mixing Console Design

ELE 791 :: Assignments n Expectations: 3xx, 5xx, 7xx n Assignment # 1 Assignment # 1 n Assignment # 2

ELE 791 :: Simple System Design Tasks Determine: Block diagram, Flowchart, Components, Interface signals, Clocking, Memory, Processor speed, Host communications requirements. Justify choices! n TASK 1 :: Peak Predictor vs Reality :: Analog stereo line level audio in and out; low frequency amplitude prediction on both channels; host adjusts digital gain; host displays predicted + real peaks of input n TASK 2 :: Dancing Lights :: Analog stereo mic level in, line level out; music application; 1024 FFT on each channel ; host adjusts digital gain; host displays input spectrum n TASK 3 :: Fading to Black :: Analog camera video signal in and out; host adjusts fade to black with variable time; host displays average luminance and average chrominance of input and output n TASK 4 :: How much Color? :: Analog camera video signal in and out; host adjusts amount of color; host displays average luminance and average chrominance of input and output

ELE 791 :: Digital Mixing Console Design n Have you ever seen a mixing console? –In some ways it could be considered the ultimate audio signal processing device –Have you attended a concert? –Have you listened to a CD? –Have you listened to the radio? n 3 broad CATEGORIES of mixing consoles: –Live Sound –Recording –Broadcast

ELE 791 :: Digital Mixing Console Design n FUNCTIONS of an audio mixing console: –nerve center of a control room –mixes various signals from different sources –allows control over signal level and spectral balance –allows signals to be routed to different destinations –allows of copies of signals to be sent to different devices and then recombined –allows signal paths to be monitored and allows corrective action to be taken –

ELE 791 :: Digital Mixing Console Design n Wheatstone Corporation Wheatstone Corporation –20 years old analog company specialized in making high- end audio mixing consoles for broadcast applications –Had a desire to migrate to digital technology n Product Line –Radio Console [least complicated, 24/7 operation]Radio Console Current Example :: Analog :: A-5000, BrochureA-5000Brochure Current Example :: Digital :: D-4000, Brochure, D-8000 FlowD-4000BrochureD-8000 Flow –Production Console [more complicated]Production Console Current Example: SP-8, BrochureSP-8Brochure –Television Console [even more complicated, 24/7 operation]Television Console Current Example: D-5.1, BrochureD-5.1Brochure

ELE 791 :: Digital Mixing Console Design n GOALS: –Shall be a drop-in replacement for existing analog consoles –Shall present the same familiar work surface to the user –Shall be upgradeable -- from completely analog to completely digital or somewhere in between –Shall have the bells and whistles normally associated with digital products – reconfigurable, external control, etc. –Shall serve as a platform for future products

ELE 791 :: Digital Mixing Console Design n TASK: –Good news: start from scratch –Bad news: start from scratch n MARKETPLACE: –Digital Recording consoles were starting to appear –All broadcast consoles were analog –Wheatstone was considered a leader in this field: CNN, ABC, The White House, … n QUESTIONS: –What kind of console should be built? –How would we architect the system?