QuestionI have a 2008 silverado w/the bose system, I want to keep my stock system & add on subs. What wires do I tap into for the line converter since the system is amplified?
AnswerHi Drew,
Good question! In your truck, there's only one good spot to tap a line-output converter for a sub amp, and it's not the easiest to reach.
With most factory-amplified audio systems, the best place to tap a LOC is between the amplifier and the speakers. The important thing is to choose a speaker output that's carrying the audio range you want to reproduce. For example, a factory amp might have separate outputs for stock tweeters, mid-range drivers and subwoofers. When you're connecting a line output converter for a subwoofer amp, the logical place to connect is to the factory subwoofer wiring. This way, you'll know that the factory wiring is carrying the bass content that you'll want to use for your after-market subs. The outputs to the other speakers might have the bass filtered out at the factory amplifier, so they wouldn't be useful for the LOC.
In your truck, the subwoofer is located at the front of the center console. The factory amplifier is located under the rear of the center console, and the wires run directly from the amp to the sub. In order to tap the stock subwoofer wires for your line output converter, you'll have to take the center console apart and get to the amp.
You should find the amplifier under the center console storage area, two plugs facing the rear of the truck. The subwoofer output wiring is in the smaller of the two plugs. There are two output channels, as it's a dual voice coil sub. One channel uses a dark blue wire with a white stripe, and a light green wire with a black stripe; the dark blue wire is positive. The other subwoofer channel uses a dark green wire, and a light blue wire with a black stripe; the green wire is positive in this channel. You can use one channel for your LOC's left speaker input, and the other channel for the right speaker input. The nice thing about these outputs is that they're a mono, non-fading signal, so both channels will carry the exact same signal and they won't be affected by the balance and fader controls on the head unit. This is ideal for a subwoofer amp.
If you haven't purchased your line-output converter yet, you might want to consider a model with a signal-sensing amp remote output. This is because it's very difficult, in a newer GM vehicle, to find a switched power source that can be used for an amp turn-on voltage. A signal-sensing turn-on circuit will take care of this problem for you, switching the amplifier on when there's an output from the factory amp, and switching off again when the system is off. An example of a line output converter with this feature is PAC Audio's SNI-45T.
Another device you might want to consider is PAC's LC1 line-level volume control. You can install this between the line-output converter and the after-market amplifier, and use it to easily adjust the volume of your new subs.
Hope this helps!
Brian
