Audio Engineering Explained

CHAPTER 3

Basic Sound Transmission and Operational Forces on Microphones

 

The Microphone Book by John Eargle

 

INTRODUCTION

All modern microphones benefit from electrical amplifi cation and thus are designed primarily to sample a sound field rather than take power from it. In order to understand how microphones work from the physical and engineering points of view, we must understand the basics of sound transmission in air. We base our discussion on sinusoidal wave generation, since sine waves can be considered the building blocks of most audible sound phenomena. Sound transmission in both plane and spherical waves will be discussed, both in free and enclosed spaces. Power relationships and the concept of the decibel are developed. Finally, ...