I don't know what kind of system you're running, but if you haven't changed your HU, you're not going to notice much of a difference.
It seems that when people put a new, better HU in their cars, the stock speakers sound like arse. Then, they upgrade the speakers to get the most out of their new HUs.
If you have the stock HU, you're just running a mediocre signal to great speakers.
Disclaimer: I have the stock system, think it's alright, and will change it out when I have the money. I also don't know anything for a fact.
Brian
