The Future of Sound Reinforcement()

							  The Future of Sound
   Reinforcement(?)

    Prof. David G. Meyer
School of Electrical & Computer
          Engineering
             Outline
• Sound Reinforcement System Design
  Goals
• Factors Which Complicate Sound
  Reinforcement System Design
• Proven Ways to Design Sound
  Reinforcement Systems
• New Developments
• Summary / Conclusions
 Sound Reinforcement System
        Design Goals
• evenness of coverage
• intelligibility (articulation loss of consonants)
• ratio of direct sound field to reverberant
  sound field
• gain before feedback
• SPL at furthest listening position
• frequency range/response
• smoothness of frequency response curve
• locality of reference
• headroom
      Factors Which Complicate
       Sound System Design
•   reverberation / echo
•   early / late arrivals
•   room surfaces (absorption)
•   room geometry
•   seating characteristics
•   variable fill
•   empty room  full room
 Proven Ways to Design Sound
    Reinforcement Systems
• central cluster
     excellent coverage
     high intelligibility
     high gain before feedback
     smooth frequency response
     good locality of reference
  –   cluster needs to be large for long, narrow room
  –   potential for interference in driver overlap regions
  –   hard to hide architecturally
  –   “ugly hanging mess”
Central Vertical Line Array
 Proven Ways to Design Sound
    Reinforcement Systems
• split source / “point and shoot”
   best if multi-channel
   high intelligibility
   potential solution for challenging room geometries
   generally more aesthetically pleasing (but not
    always)
  – potential for creating large interference zone
  – potential for loss of locality of reference
  – potential for limited frequency range over which
    directional control is possible
Split Source / “Point and Shoot”
 Proven Ways to Design Sound
    Reinforcement Systems
• distributed / delayed
   good solution for large, absorptive rooms with low
    ceilings
   potential solution for challenging room geometries
   potential solution for reinforcing “distant” zones
  – requires digital delays / multiple amplifiers
    (expensive)
  – potential for loss of locality of reference
  – generally not well suited for rooms with high
    ceilings (or that are highly reverberant)
Distributed / Delayed
           New Developments
•   Before its time in ’89…
•   Renkus-Heinz Iconyx
•   Yamaha YSP-1
•   Pioneer PDSP-1
•   Sounds Good
•   Patent 7130430
Back to the problematic
 long, narrow room…
15+ years later…
http://www.yamaha.com/yec/soundprojectors/
http://www.pioneer.eu/eur/content/press/news_20021010_PDSP1.html
                                      ECE 477 Digital Systems Senior Design Project  Spring 2007
                                          SOUNDS GOOD / DS3 Digital Steerable Sound System
                                           Joe Land, Ben Fogle, James O’Carroll, Elizabeth Strehlow
       PROJECT DESCRIPTION:
                                                       USER MENUS CONCEPT:                            USER INTERFACE UNIT:
       -Digitally Steerable Sound
       System, allows for non-ideal
       placement of speakers
       -Six Preset Equalization Modes
       -Wireless Control Interface
                                                                PCB LAYOUT:

          ILLUSTRATION OF
          CONCEPT:                                                                                      LOUDSPEAKER UNIT:




                                                       Top Copper           Bottom Copper

                                                               SIGNAL PATH:




                                                                                                      FRONT          BACK
Digijock(ette)-Strength
Digital System
       Back to the future?




2006                         1981
      Summary / Conclusions
• there is no universal, “one size fits all”
  solution to sound reinforcement system
  design
• knowledge of physics (sound propagation,
  room acoustics), electrical engineering
  (amplifier technology, wireless microphones),
  and computer engineering (digital signal
  processing, network technology, system
  monitoring, automation/control) are all helpful
  in formulating an optimal solution
• there are some new, exciting possibilities!