Someone kindly told me that Mazda 3 only has 10RMS from its head unit, and I just bought a pair of Infinity reference 6802cf and a pair of Polk db570 for rear, does these speaker need more RMS to function? or I'll be fine with them power by Head Unit?
Ditto... all speakers are better if they get amp power... but those particular ones are very sensitive. That means that they make more noise with less power. So as far as aftermarket speakers running of the stock HU.. those are a good choice.