Walk through a lot of car shows and you'll be violated by a variety of sounds. If you're lucky, those sounds will be coming from engines, but more often than not, the music will be unfamiliar to you. Car stereo systems have gotten beyond ridiculous lately, and when all is said and done, the bill for these battery-draining wonders is usually more than GM's debt.
It's possible to have good tunes without hiding money from the government, although the show systems of today are somewhat interesting-the extra weight, cost, and loss of space is more than the typical Jeeper can bear. (The choice of a toolbox or a speaker box is no choice.) Even our guitar-blazing Hazel could come to the right conclusion.
An audio snob would tell us not to waste our time or money installing a decent sound system in a Jeep. Lucky for us, we don't give a rat's ass. We put a call into Sony for some advice on what to do in a CJ for sound, with three requests: weatherproof parts, small space, and the ability to play all of those MP3s we ripped off before Napster got slammed by those whiners from Metallica (as if they weren't rich enough already). Sony recommended a CD head unit with disc-changer control. That means we could have 11 CDs at our disposal. A pair of two-way marine (weatherproof) speakers and an 8-inch subwoofer are driven by a 600-watt amplifier that doubles as a space heater.
Our Scrambler has hard doors...
Our Scrambler has hard doors that are as shallow as Los Angeles women. There's not much room for speakers, so it's important to measure the depth of the speakers you wish to use and check for clearance.
The Sony head unit comes with...
The Sony head unit comes with a removable face to deter some jackass from stealing your system. Also included is a remote control, which seemed completely ridiculous, but once we got used to having it for changing volume or CDs while driving, it was handy.
We mounted the weatherproof...
We mounted the weatherproof speakers and ran the wires on the limiting strap for the doors. You can route them through the doorjamb, but you may be risking a pinched or shorted wire.
It seems like a lot of equipment to fit in our half-cab Scrambler, but it fits. If you hate to see a CJ cut for sound equipment, you can stop reading now.
The CJ never came with the massive amounts of foam padding or rubber insulation to reduce NVH (noise, vibration, and harshness). Mud tires and the wonderful 4.2L jackhammer under the hood scream freely. So before installing the tunes, we hit our local hardware store for an inexpensive way to quiet things down.
Bass: Lower frequencies of sound, usually characterized by boom boom.
Subwoofer: The speaker for bass sound.
Mid-range: Middle frequencies of sound, like a guitar.
High-range: High frequencies of sound, like a whistle.
12 volts constant: A source of power that never drops in voltage unless the battery is dead. It's usually used to retain memory, like preset radio stations on the head unit.
12 volts switched: A source of power that supplies 12 volts when the ignition is turned on.
12-volt turn on: Supplies 12 volts when the head unit is turned on. It's used for putting a power antenna in the air or turning on the amplifier.
Ground: The negative side of a car battery is connected to the vehicle chassis. Almost any clean, bare metal surface can be used as a ground.
RCA cables: Used to transport low-level sound to the amplifier. Keeping the sound strength low allows for a cleaner sound after it's amplified.
Head unit: The brains behind the system located right in front of the driver.
Amplifier: Boosts the power of the sound created by the head unit and creates torque for sound.
Disc changer: A unit that stores multiple CDs or DVDs and can be controlled by the head unit.
NVH: Noise, vibration, and harshness is a term used mostly by the OEMs to grade the effects a vehicle has on the human body under driving conditions. For instance: a New York subway with a plastic seat in the summer heat next to some bum who just vomited on himself has pretty lousy NVH.
Jackass: Someone who tries or succeeds in stealing your stereo.
Bad luck: When your girlfriend moves out and takes the film you shot for a story.
After yanking out the seats,...
After yanking out the seats, we lined the floorpan with insulated foil wrap. It deflects heat and sound while conforming well to the stamped metal floor. It's experimental, but we opted to use a bathtub liner as additional sound-deadening material. We cut it into specific shapes and taped it to the foil wrap in places we felt sound would be an issue.
The Scrambler's floor looked...
The Scrambler's floor looked like a quilt job gone bad. We bugged ol' Mikey Sailsbury at Collins Bros. for some advice on carpet. He recommended the full CJ carpet kit (pictured).
The 8-inch subwoofer wasn't...
The 8-inch subwoofer wasn't going to fit in the door, and we didn't want to give up any additional space behind the seats. Being infinitely clever folks, we opted to build a center console that doubles as a speaker box. Sony recommended at least one cubic foot of air space in a sealed box. We measured it out, blobbed silicone sealant on the seams for an airtight fit, and covered the console with leftover carpet.
All lines end here. The Sony...
All lines end here. The Sony amplifier (right) is the hub for delivering high-power sound to the speakers. We cut out a piece of particle board to fit neatly behind the seats for mounting the amplifier and disc changer. We have a half-cab, so we didn't need all of the carpet kit, and some of the extra pieces were used to cover the new panel. The amplifier is equipped with a built-in crossover. That doesn't mean crap to most people, but the idea is to get only bass sounds to come from the woofer and mid-range/high sounds to come out of the smaller door speakers. A crossover helps stop distortion by separating the music and delivering it to the correct speakers.
It's important to run a 12-gauge...
It's important to run a 12-gauge or larger power line directly from the battery to the amplifier with an inline fuse at the battery. The amplifier uses more juice than Schwarzenegger and needs a constant (uninterrupted) supply of power. This line should be several inches from all RCA cables (the cables that transfer sound from the head unit to the amplifier). The voltage running through the 12-volt wire can create a small magnetic field, which causes unwanted electric noise in the speakers. After the head unit was installed, we routed the necessary cables and wires to a location behind the seats for the amplifier.
The new Sony head unit uses...
The new Sony head unit uses what's called a DIN (large rectangle) mount, but the factory CJ dash has a two-knob (two holes and a small rectangle) setup. We marked the area for trimming and taped the edges so we wouldn't scratch outside the lines. It's important to view and measure behind the dash for space and to avoid damage to wires and brackets. We used a small cut-off saw to remove the excess material. The head unit comes with a metal cage for proper mounting. This may look difficult, but the directions are very easy to follow and give great explanations of each wire and the purpose. It's much like hooking up a home stereo system with 12 volts instead of 110. We used the factory radio wiring for most connections and ran necessary cables to the back of the cab for the other equipment.