With a degree in mechanical engineering, Mark Eldridge did his homework before getting serious with the install in his 1987 Toyota 4-Runner. He purchased a Techron TEF System 20 HI professional computerized acoustical measurement device in order to learn more about the vehicle's acoustical environment and to help him plan out the system.
Up front, Eldridge rebuilt the dash to install horn-loaded compression drivers behind it. He also tinkered with the passenger side, raising it to make it symmetrical with the driver's side. The Alpine 7909 CD tuner was mounted at center.
In the kick panels, Eldridge loaded 8-inch JBL midbasses in aperiodic enclosure. Another pair of aperiodic enclosures hold Kicker 12-inch subwoofers in the trunk. To conserve space, Eldridge built them around eah base of the 4Runner's roll bar. To make room for the amps and processors, he raised the floor of the cargo space by 5 inches. Normally, the liquid-cooled Kicker amps are hidden beneath a carpeted panel.
Here are some of the other vehicles we've featured in our 20th anniversary retrospective: