As we enter a new millennium, you would think that the very mature field of loudspeaker engineering would have mostly exhausted itself of new concepts and ideas. However, I m happy to report that this simply isn t the case. It s been nearly a quarter of a century since I began writing the first edition of the LDC, and I m still learning new and fascinating aspects of the art of loudspeaker design on an almost daily basis. The LDC 6^ edition certainly reflects this fact. There is a substantial amount of new information in this latest revision, significantly more than the 5th edition released in 1995. In fact, the quantity of both references and graphs increased by close to 50. There were 191 references and 370 graphs and drawings in the 5th edition and to this the 6^ edition has added 83 references and 214 graphs and drawings. Some of the highlights of this new material include:

- a tutorial on low-frequency woofer design in terms of driver motor parts (voice coils, plates, poles, cones, spiders, surrounds, and magnets) instead of just parameters (courtesy of Red Rock Acoustics and its new transducer engineering software SpeaD)
- an explication of high-frequency woofer design aspects showing the effects of different kinds of dustcaps, surrounds, and motor configurations
- curvilinear vents
- Dr. Earl Geddes new Acoustic Lever enclosure design
- a completely new TL chapter
- a tutorial on midrange bandpass and tweeter high-pass attenuation circuits
- a look at loudspeaker CAD software (including a new section on room design software and analyzers)
- a discussion of dipole versus direct radiator surrounds, as well as the theory and details behind the new rear-channel surround system, Surround EX (Dolby Digital 6.1)
- new ideas for achieving better speaker imaging in the car
- and last, an entirely new chapter, Chapter 12, which is a kind of cut-down version of what I attempted to do in the Loudspeaker Recipes book: provide a comprehensive speaker design tutorial. The Recipes book required 400 or so graphs to explain the functioning of four two-way designs, each using a different design methodology to achieve a flat summation given inter-driver time delays. Chapter 12 contains two projects: a complete home theater system including LCR, surrounds, and powered subwoofer; plus something dear to my heart, a very high performance studio monitor. While these are presented in the form of construction articles, as in the Loudspeaker Recipes book, Chapter 12 is really an extensive speaker design tutorial and tells the story using some 107 graphs and drawings.

I sincerely hope you enjoy reading this new material as much as I have enjoyed researching and writing it.