User Guide

Sound System Design Reference Manual
Table of Contents (cont.)
Chapter 6: Behavior of Sound Systems Indoors ......................................................................... 6-1
Introduction ....................................................................................................................................... 6-1
Acoustical Feedback and Potential System Gain ............................................................................. 6-2
Sound Field Calculations for a Small Room ..................................................................................... 6-2
Calculations for a Medium-Size Room ............................................................................................. 6-5
Calculations for a Distributed Loudspeaker System ......................................................................... 6-8
System Gain vs. Frequency Response ............................................................................................ 6-9
The Indoor Gain Equation ................................................................................................................ 6-9
Measuring Sound System Gain ........................................................................................................ 6-10
General Requirements for Speech Intelligibility................................................................................ 6-11
The Role of Time Delay in Sound Reinforcement ............................................................................ 6-16
System Equalization and Power Response of Loudspeakers .......................................................... 6-17
System Design Overview ................................................................................................................. 6-19
Chapter 7: System Architecture and Layout ................................................................................ 7-1
Introduction ....................................................................................................................................... 7-1
Typical Signal Flow Diagram ............................................................................................................ 7-1
Amplifier and Loudspeaker Power Ratings ...................................................................................... 7-5
Wire Gauges and Line Losses ......................................................................................................... 7-5
Constant Voltage Distribution Systems (70-volt lines) ...................................................................... 7-6
Low Frequency Augmentation—Subwoofers ................................................................................... 7-6
Case Study A: A Speech and Music System for a Large Evangelical Church .................................. 7-9
Case Study B: A Distributed Sound Reinforcement System for a Large Liturgical Church .............. 7-12
Case Study C: Specifications for a Distributed Sound System Comprising a Ballroom,
Small Meeting Space, and Social/Bar Area ............................................................................... 7-16
Bibliography