Speakers

Bryce's Speaker Building
Information about building speakers for DIY projects.
http://www.angelfire.com/music5/s_building/index2.html

eBuying Guides: Where to Buy Speakers/Headphones
Concentrates on where to shop for products, but also has staff-produced buying guides. Some of the guides are links to other buying guide sites.
http://www.ebuyingguides.com/where/speakers_w.htm

Epinions: Computer Speakers
Comparisons and reviews written by consumers.
http://www.epinions.com/cmhd-Speakers-All

Epinions: Speakers
Consumer-generated reviews, buying tips and advice, ratings, price information, and searchable in a variety of ways from price to product type.
http://www.epinions.com/elec-Audio-Components-Speakers-All

High Efficiency (Exponential) Loudspeaker Set For Disco Application
Physics principles, calculations, drawings, specifications, pictures, and internet resources/references. PDF version of the site available as well.
http://www.home.zonnet.nl/andre.barel/loudspeaker.htm

ReviewCentre.com: Speaker Reviews
Consumer reviews on speakers.
http://www.reviewcentre.com/items21.php3

Subwoofers - What You Need To Know
Explains types, crossovers, alternatives, shopping and installation tips.
http://hometheater.about.com/cs/loudspeakers/a/aasubwoofera.htm