Depends on what you will be using the LOC for. If you are doing a 4 channel amp install using a 2 or 4 channel LOC would differ slightly. If you are doing a sub amp install you can tap to any of your speaker lines and you are ready to roll. You might want to provide some more insight as far as what you are trying to achieve with the LOC, (2 channel amp, 4 channel amp, mono amp) because you could lose the fading & balance function of your HU if you are using the 2 channel LOC as opposed to the 4 channel LOC. Also, include the make and model of your vehicle. Someone might have already done it on a similar vehicle and could walk you through it.