Hello, I have a Pioneer headset that is 50 watts x 4. I want to change my stock speakers in my car (4). I'll buy 4 speaker kenwood that are 220 watts. 1. Now, does that mean that my speakers will only run 1/4.4 of thier power? 2. What are ohms? 3. I'd like to buy a ampli and subwoofer too so if I buy a ampli that has: - 250 watts x 1 under 2 ohms - 125 watts x 1 under 4 ohms What does that mean? What specs should I look at when buying my sub and ampli? Thank you!!