HEATKEYS

Provides bandpass, sealed and vented subwoofer box design software and science, math and engineering programs and freeware

Atrend is the global leader in subwoofer enclosures. Our speaker boxes are manufactured by our staff of experienced audio professionals. We bring the boom so you don

Car audio help offers free information on car audio, car stereo, mobile video, satellite radio, a free newsletter and specialty articles on various topics from buying and installing car stereo equipment to maintaining and troubleshooting.

The web

Yahoo! Answers is a new way to find and share information. You can ask questions on any topic, get answers from real people, and share your insights and experience.

The online community for car audio beginners, enthusiasts and professionals. Find, compare and review the hottest car audio components, installers and installation shops in the world. Buy or sell your car stereo gear in our free online classifieds, s...

The Internet

F150online is a discussion forum for current and late-model Ford trucks, from 1997 to present.

Instructables is the Biggest How To and DIY community where people make and share inspiring, entertaining, and useful projects, recipes, and hacks.

DIY Audio and Video: FAQs, Tutorials, and Calculators for Speaker Boxes, Crossovers, Filters, Wiring and more.

SpeakerBuilding.com is a resource for DIY loudspeaker design and construction.

Car audio technical information with more than 125 individual pages, 50+ calculators and wav files. The covered topics range from basic electronics theory to more advanced topics such as speaker impedance as it relates to frequency, damping factor a...