"Audio, Acoustics & Perception" chap 4 online

The fourth chapter of Earl Geddes' book has been written and is now posted online at:


This chapter, on Measurements, is quite eye-opening. Among the things that really stood out to me is a comparison of Figure 4-6, the very similar on-axis responses of two loudspeakers, with Figure 4-10, which shows the power response of the same two speakers. Earl is an advocate of measurements as a relaible means of evaluating a loudspeaker, but he makes a very strong case that it takes a very thorough set of measurements to do this. The preceeding chapter, on Psychoacoustics, helps set the stage for this one and is well worth reading also.

Earl will take down earlier chapters as new ones are posted, and the first (introductory) chapter is gone already. After he has posted them all, he'll take down the remaining ones and the book will only be available in hard copy. But he doesn't mind if you want to download and save the chapters as he posts them - he has made no requests that we not do so.

Disclaimer - Earl Geddes is a friend of mine. I'm doing some minor proofreading work for Earl on this project, and I'm a dealer for his speakers.

Earl isn't exactly well known as most of his work has been in professional applications, but here's a link to his resume' in case you'd like to see what his qualifications are. His patents start about halfway down the page:


Enjoy the book for free, while we can!