Audio Systems: Adding Subwoofers to Stock Radio, two subs, stock radio

Question
Hi. I have a 2006 Impala LT with the XM stock radio (no onstar). I am trying to find instructions for removal of the radio, for one. Does the radio has preamp hookups in the back? I would really like to keep the factory radio and just add a pair of subs in the back. Is this possible and if so, what do I need.

Answer
Yes, you can add one or two subs. Usually, one good sub is a better choice than two. Why? Because one takes less space and costs much less AND will produce sufficient sound.

Most head units already have a sub output that feeds directly to a powered sub unit.

But, I will give you a few alternative solutions:

http://www.sjgreatdeals.com/sisloc80.html

The above allows you to just tap into the speaker outputs from the in-dash radio without removing it and it will give you two audio outputs for external amp with two power amps to two subs or other speakers. You may need a crossover with this solution.

http://www.avtoybox.com/car-stereo---video-mobile-installation-line-out-converte...

The above shows more line-out converters.

http://www.installer.com/hilo/

The above shows many units, but if you scan down a little you will find adaptors for adding sub to oem units.  Model is:  LOCSUBA  SOUNDGATE

For getting at the radio back side I have no personal experience on pulling the unit out.  Below is a procedure for an older model, but it may still be useful to some extent in giving you ideas on how GM is doing it now days.

http://www.installdr.com/InstallDocs/GM/PDF/460041.pdf

And, below, for a fee, you can purchase a detailed manual that may help you get it out properly.

http://www.carstereoremoval.com/htm/stereoremovalChevroletImpala00_03P.htm

So, after reading all this you may find it confusing, but distill your remaining questions and let me know more what you decided and I can help you zero in on the right solution.

C