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

Digijock(ette)-Strength Digital System DesignTM

PROJECT DESCRIPTION:

-Digitally Steerable Sound System, allows for non-ideal placement of speakers

-Six Preset Equalization Modes

-Wireless Control Interface

Joe Land, Ben Fogle, James O’Carroll, Elizabeth Strehlow

ILLUSTRATION OF CONCEPT:

USER MENUS CONCEPT:

PCB LAYOUT:

LOUDSPEAKER UNIT:

FRONT BACK

Top Copper Bottom Copper

USER INTERFACE UNIT:

SIGNAL PATH:

2006 1981

Back to the future?

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!