Car Stereos: GMC Denali subwoofer, line level inputs, gmc denali

Question
Brian, I am following up on your response to the other gentleman with a 2009 denali.  I would like to improve the sub in mine as well, and have a sub box with 2 12inch kickers and a seperate amp from my previous truck.  Can I just feed the audio signal off the main amp (under the console) to my new amp?  Can I send just send one voice coil to one of my kickers and one to the other and bypass my seperate amp?  Any other thoughts?  the system is otherwise fine except it needs cleaner and lower bass out put.

Answer
Hi Richard,

You can certainly use the factory amp's subwoofer output to supply a signal for your after-market amp.  Depending on your amplifier, you may need to use a line-output converter to change the factory high-level output to match the after-market amp's line-level inputs.  If you get a line output converter, pick a model with a built-in signal-sensing turn-on circuit, because there are very few places in a 2009 Denali where you can attach an amplifier's remote turn-on lead.

You don't need a line-out converter if your amplifier has high-level inputs with its own signal-sensing turn-on feature.  In this case, you could just connect the amp's high-level inputs directly to the factory amp's subwoofer output.  Unfortunately, while high-level inputs are common on many after-market amplifiers, a signal-sensing turn-on circuit isn't a very common feature.

You can disconnect the stock sub or leave it connected, whichever you choose; but I wouldn't try to use the factory sub outputs to drive your 12" speakers directly.  Your after-market amp is likely to have much more power than the factory amp's output, so I'd use the after-market amp for best results.

Hope this helps!

Brian