Car Stereos: 2001 toyota avalon stereo, dual voice coils, rms output

Question
I want to keep the original stereo, but I want a better system. The back speakers are blown but the front work fine. I want to get subwoofers and an amp.  What would you suggest(affordable) I get that would be a good fit with what I already have? Does rms output need to match if I am using an external amp?

Answer
Amanda,  Sounds like a good plan.  I would replace all your factory speakers with aftermarket speakers made by MB Quart, Infinity, or Alpine.  Once you get the factory speakers replaced, you should hear a big difference in sound quality.  If you want to pump up the bass and really make it sound good, then you start looking for an amp and subs.  When looking for an amp, you want to get one that puts out about twice as much "rms" watts than your stereo.  Most factory stereos put out around 18 - 24 "rms" watts.  So, a 50 "rms" watt amp is all you need for your subs.  As for subs, you just need to make sure the "rms" rating is higher than the amps.  I prefer using two subs, one for right channel and one for left channel, but they require some space in the trunk.  Some people use a single sub and use the amp to bridge the two channels together. Or, they use a sub with dual voice coils to attach each channel to.  Either way, if you do go with a single sub, it will use half the space needed for two subs.  Normal space required for each sub is between 1 and 1.5 cubic feet.  Hope this helps, Scott