Try starting off with books by David Weems and then move up to Vance Dickason's Loudspeaker Design Cookbook. You can probably obtain these through your local library or do an inter-library loan. That is, if you live in a populated area : ) Sean
Only two responses?
What do you want to learn? Want to build something or just learn? There is a wealth of information online. You will find a fair amount of the sites by reading at this Madisound Speaker Building forum for a short while. http://www.madisound.com/cgi-bin/discuss.cgi and asking a question or two there.
One thing to remember is that you might find books about speakers a little hard to follow w/o some basic knowledge about electricity first. In my opinion there is just no avoiding this. You will not get a lot of enjoyment out of Dickason without it. It is just the way it is. Most books about speakers take a certain familiarity with basic concepts (voltage, current, impedance, phase, back emf, magnetism, electrical resonance, Q, etc...) for granted and speakers just cant be understood without them.
A couple helpful sites re speakers with articles for starting out:
http://www.adireaudio.com/ (read the tech area)
(look at the resources section here)
Some online sources for basic electricity. Rays is a really good short (50 pages) on the basics and only takes a few hours to read:
Ray Dall, Electronics Theory.com:
Tony R. Kuphaldt, Lessons in Electric Circuits (LEC):
There are some good intro sections on capacitors and filters in this material
Graham Knotts Basic Electronics (Cambridge Regional College) Excellent!
Basic Electronics (dont let car foolya) This is a car site but basic electricity section is very user friendly
If you are really into it some basic books on electricity that are good for non-tech folk.
*Van Valkenburgh, Nooger & Neville: Basic Electricity. This book really holds your hand through the basic concepts.
*Bureau of Navy Personnel, Basic Electricity. An introduction to electricity
*Army Technical Manuals (1951-52). These are very good if you are beginning. Often available on E-bay for bargain prices. TM11-681 has a very clearly written appendix on the use of trigonometry for ac/phase theory. TM11-661, Electrical Fundamentals (direct current); TM11-681 Electrical Fundamentals (alternating current)
Both books Sean notes are good.