ELE 791Real World Signal Processing
Spring 2005
Syracuse University
22 Feb 2005
ELE 791 :: Outline [22 Feb 2005]
nAssignments
nSimple System Design Tasks
nDigital Mixing Console Design
ELE 791 :: Assignments
ELE 791 :: Simple System Design Tasks
Determine: Block diagram, Flowchart, Components,Interface signals, Clocking, Memory, Processor speed,Host communications requirements. Justify choices!
nTASK 1 :: Peak Predictor vs Reality :: Analog stereo line levelaudio in and out; low frequency amplitude prediction on both channels;host adjusts digital gain; host displays predicted + real peaks of input
nTASK 2 :: Dancing Lights :: Analog stereo mic level in, line levelout; music application; 1024 FFT on each channel ; host adjusts digitalgain; host displays input spectrum
nTASK 3 :: Fading to Black :: Analog camera video signal in andout; host adjusts fade to black with variable time; host displays averageluminance and average chrominance of input and output
nTASK 4 :: How much Color? :: Analog camera video signal in andout; host adjusts amount of color; host displays average luminance andaverage chrominance of input and output
ELE 791 :: Digital Mixing Console Design
nHave you ever seen a mixing console?
–In some ways it could be considered the ultimateaudio signal processing device
–Have you attended a concert?
–Have you listened to a CD?
–Have you listened to the radio?
n3 broad CATEGORIES of mixing consoles:
–Live Sound
–Recording
–Broadcast
ELE 791 :: Digital Mixing Console Design
nFUNCTIONS of an audio mixing console:
–nerve center of a control room
–mixes various signals from different sources
–allows control over signal level and spectralbalance
–allows signals to be routed to different destinations
–allows of copies of signals to be sent to differentdevices and then recombined
–allows signal paths to be monitored and allowscorrective action to be taken
–http://www.audioed.com.au/LearnOL_synopses/MIXER1Free_synop.html
ELE 791 :: Digital Mixing Console Design
–20 years old analog company specialized in making high-end audio mixing consoles for broadcast applications
–Had a desire to migrate to digital technology
nProduct Line
ELE 791 :: Digital Mixing Console Design
nGOALS:
–Shall be a drop-in replacement for existing analogconsoles
–Shall present the same familiar work surface tothe user
–Shall be upgradeable -- from completely analog tocompletely digital or somewhere in between
–Shall have the bells and whistles normallyassociated with digital products – reconfigurable,external control, etc.
–Shall serve as a platform for future products
ELE 791 :: Digital Mixing Console Design
nTASK:
–Good news: start from scratch
–Bad news: start from scratch
nMARKETPLACE:
–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, …
nQUESTIONS:
–What kind of console should be built?
–How would we architect the system?