Car Stereos: factory deck, active noise control, stock speakers

Question
how would i install a amp and subwoofer to a factory deck for a 2008 honda accord non navi unit

Answer
Hi Tony,

Installing an after-market amplifier with a factory head unit is usually a fairly simple process, but your vehicle may have a feature that makes things a bit more complicated.

Virtually no factory head units include RCA outputs for use with after-market amplifiers, so a new amp will need to be connected to the factory speaker wiring.  In your car, the easiest way to do this is to find the wires leading to the rear speakers, under the rear deck in the trunk.

Many amplifiers have what's called a "speaker-level" or "high-level" input.  If your amplifier is so equipped, you can just run wires from the high-level input terminals to the factory speaker wiring.  The new amp will get use the audio signal from the speaker wires; the stock speakers can remain connected.

If you don't have speaker-level inputs on your amp, then you'll need a device called a line output converter.  This also connects to the factory speaker wiring, but it converts the signal to a low-level, RCA output that can be used with any amplifier.

Many Honda Accord models are equipped with a feature called ANC--Active Noise Control.  If your Accord is a 6-cylinder automatic, it has the ANC feature; if it's a 4-cylinder, then the ANC feature is an option.

ANC works by picking up low-level sounds through a pair of microphones, then plays the sound through the factory speakers with the phase reversed.  This has the effect of canceling some of the low frequency rumble produced by the vehicle's drive train.  It's similar to the way that noise-canceling headphones work; however, it causes problems with after-market amplifiers.  The ANC signal in the speakers is picked up by the amplifier, and reproduced through the subs; so you get a constant rumble in your subwoofers.

If your Accord is equipped with ANC, it will need to be disabled if you want to add an after-market amplifier and subwoofers.  In order to disable the ANC feature, you have to disconnect the ANC microphones.  There are two, both located in the headliner; one is near the front, and one near the rear.  Unplugging the mics will disable the ANC, but if your car is equipped with a factory Bluetooth hands-free phone system, this will also be disabled when you disconnect the front microphone.

Hope this helps!

Brian