Adding subwoofers and amplifiers is a sure way to provide the balance and power found in a complete sound system. There are no substitutes for the depth of sound that can be achieved with subwoofers powered by amplifiers. You need to make sure that the output levels of the amplifier are safely within the range of the subwoofers you wish to install. Also you need to make sure that you connect the subwoofers in a parallel circuit to avoid over-loading the amplifier. You can have a technician at an aftermarket retailer perform the installation, or you can install the amp and subs into your Escalade EXT yourself and save the cost of labor.
Disconnect the negative battery cable from the Cadillac battery. Use a Phillips head screwdriver to loosen the negative cable's clamp. Remove the clamp from the negative lead post and rest it away from the lead until the installation is complete.
Drill an opening in the firewall. The new hole should be near the battery and go through to the footwell of the driver's side of the Escalade. Place a rubber grommet into the new opening to protect the cable that will be routed through the hole.
Connect the amplifier ring terminal included in the amplifier wiring kit to the positive battery lead. The ring terminal will have the power supply cable attached. Route the power supply cable to the inside of the cabin through the firewall.
Remove the dash trim panel surrounding the stereo. Use a trim panel removal tool, wrapped with a thin cloth to protect the finish of the panel, to pry the panel free from the dash. Unscrew the four screws holding the stereo to the mounting bracket with a Phillips head screwdriver. Pull the radio from the dash to access the wiring in the rear of the unit.
Disconnect the wiring to the back of the Cadillac's stereo. Connect the stereo wiring to a wiring harness adapter. Connect the wiring harness adapter leads to the stereo. Connect the signal cable and turn-on lead from the amp wiring kit to the wiring harness adapter. Route the signal cable and turn-on lead through the back of the empty stereo dock and down to the floor of the vehicle on the passenger's side.
Replace the stereo into the dash of the Escalade. Screw in the four perimeter screws and replace the trim panel by hand.
Remove the trim panels that secure the carpeting to the floor of the vehicle using a trim panel removal tool. The panels can be simply pried from the flooring and replaced by hand with a moderate amount of force.
Lay the cables (power supply, signal cable and turn-on lead) from both sides of the vehicle, beneath the carpeting, to the rear seat.
Place the amplifier beneath the driver's side rear seat. Place plastic spacers beneath the amp to provide ventilation. Connect the cables (signal, turn-on, power supply) from the front of the vehicle to the amp. Connect a grounding wire included in the amp wiring kit from the amplifier to a bolt under the seat. Any bolt that is directly connected to the frame of the Cadillac will provide the necessary ground.
Place the subwoofers behind the seat and connect them to the amplifier with speaker wire. Connect the positive output on the amplifier to the positive input of the first subwoofer. Connect the negative output of the amp to the negative input of the first amp. Connect the negative inputs of both subs together and the positive inputs together using speaker wire.
Replace the grounding cable's clamp to the negative battery cable. Tighten the clamp with a Phillips head screwdriver.
