Where does the common wire splice to? 40 watt audiovox sound exploder

SOURCE: Wire kit for a Audiovox BA200 200 Watt base tube

There are 5 wires to connect to the BA-200 for proper operation. 1. Red Wire with Fuse: Connect this wire to a source of + 12 volts which does not turn off with the ignition key. It may also be connected directly to the po~itive (+) terminal of the battery. 2. Black Wire: Secure this wire using a screw or bolt on a grounded metal surface of the vehicle. Clean-away any rust, dirt, or paint from the surface to make sure a good connection is made. 3. Blue Wire: This wire activates the BA-200 when the stereo system is turned on. Connect it to the "Power .Antenna" lead from your car stereo. If your car stereo does not have or you cannot locate the Power Antenna lead, the blue wire can be connected to a source of + 12 volts which is turned on and off with the ignition switch. In this case, the BA-200 will be activated whenever the ignition switch is turned on, whether the car stereo is on or off. 4. Green Wire: Splice this wire to the wire going to the positive (+) terminal (sometimes indicated bya red dot) of the left speaker of your stereo system. 5. G ray Wire: Splice this wire to the wire going to the positive ( + ) terminal (sometimes indicated bya red dot) of the right speaker of your stereo system. You Need to order this piece trough the manufacturer, with out this piece the sub is useless, i am guessing around $20-$30 for it