yeah mine was like that to but eventually i installed a component of kickers 6 1/2"
i am sure you can ad some to your oem stereo but the only problem you may come across is that most oem stereos are 2 ohms configured so once you install some tweeters or a set of components it will sound nice at low volume levels but once you raise it it will not sound the best
there,s many different ways to get this done depending which one fits you the best
1- replace the oem stereo for an aftermarket-then run new components
2- buy a PAC signal processor ($35) and grab signal from your oem stereo for an aftermarket amp for your components
3- replace the oem stereo for an aftermarket then run a baby kenwood eq then an amp for your components...if you do this believe me the brand of speakers wont matter it will sound just great as if you have top notch stuff..believe me i have like that on my xterra and it just sounds amazing
my stereo is a double din PYLE brand ($200)
my eq is the baby kenwood ($150)
my amp is a 5 chanel hi fonics ($180)
rear speakers are the oem,s ($0)
front speakers are kenwoods ($100)
10" rockford fosgate woofer with sealed box ($120)
it may look like $800 but hey some guys spend $350 alone in front components and another $350 in rear components or a fancy stereo alone can be around $800 to 1,200 depending in what brand
use this if you need some reference
swap-your-cube-oem-stereo-t440221.html