This is a basic way in which you can wire a dual 4 ohm subwoofer to a 2 ohm load.
If you are looking to get the most power out of your amplifier for your sub, this is one of the best ways to wire your subwoofer. It is a traditional method of wiring that works very well. The sub will be wired in "parallel" to achieve this impedance (ohm).
Step 1: Gather the Necessary Materials and Prepare the Box
Here is the list of items that are used for this simple installation.
1 x Kicker CVX 12 Subwoofer
1 x Kicker 12 AWG Speaker Wire
1 x Kicker 750 Watt Monoblock Amplifier
1 x 20 oz. bag of Poly-Fil FiberFill
1 x Vented Sonic Sub Box Enclosure
1 x Wire Stripper/Crimper
1 x Kicker Subwoofer Grille
1 x Can of Adhesive Spray
Prepare the enclosure for installation.
The Kicker CVX subwoofer will be loaded inside of the vented box. This subwoofer is designed to be used with either a sealed or a vented box, however a vented (sometimes referred to as ported) enclosure is used for this instructable. Fill the subwoofer box with Poly-Fil. Spread the FiberFill around the inside of the box. Adding Poly-Fil simulates a larger box, which results in deeper bass. The box was filled with Poly-Fil to enhance the sound emitted from the sub box, as well as optimize the subwoofer's performance. Because the box is vented, The Poly-Fil was adhered to the box with a spray adhesive to prevent it from being pushed out the vent during use. A 2 foot section of the 12 gauge speaker wire was soldered to the back side of the box terminals to provide a secure connection.
Step 2: Cut and Prepare the Speaker Wire
Take the Kicker SW1220 speaker wire and cut two separate pieces of the blue (positive) wiring; one 1' piece and one 2' piece. Now cut two pieces of the black (negative) wiring; one 1' piece and one 2' piece.
The 2' pieces are used to connect the subwoofer to the box terminal. The 1' strands of speaker wire are used to connect the subwoofer's voice coil terminals together.
Different companies use different colors or manners to represent the positive and negative wires. Here, Kicker is using blue and black. Because the woofer is a Dual 4 ohm we are going to have to connect the two terminals on the subwoofer. To do so, a 1 foot section of positive speaker wire and a 1 foot section of negative speaker wire is cut and prepared.
Using the wire striper, strip back the wire jacket (insulation) about 1/8" to 1/4" to expose the wire.
Step 3: Wire the Positive and Negative Terminals for One Voice Coil
Press on the top of the first negative terminal to open up the terminal. Insert the stripped end of the black (negative) wire.
Then, push down on the first positive terminal and insert the stripped end of the blue (positive) wire.
Step 4: Connect the Second Negative Terminal
Push down on the first negative terminal and insert the stripped end of the second piece of black (negative) wire.
Then, take the other end of this piece and insert it into the second negative terminal.
Step 5: Connect the Second Positive Terminal
Push down on the first positive terminal and insert the stripped end of the second piece of blue (positive) wire.
Now take the other end of this piece and insert it into the second positive terminal.
Step 6: Check the Wiring and Mount the Subwoofer
Now you should have a X-crossed wiring design across the bottom of your subwoofer. This is connecting the voice coils and wiring them in a parallel configuration.
Mount the Kicker 06CVX124 subwoofer and grill into the box using screws and a power drill to drill the screws into the wood box.
The loaded subwoofer enclosure can now be connected to an amplifier that matches the ratings of the installed subwoofer. The Kicker CVX subwoofer shown was connected to a 750 Watt Kicker ZX750.1 monoblock amplifier. This is done by simply connecting the negative terminal on the enclosures terminal to the negative terminal on the amplifier. Then the positive terminal on the enclosure is connected to the positive terminal on the amplifier.