WHAT SIZE SPEAKER IN DOOR AND IN BACK SEAT?
CAN I MIXED UP THE BRANK NAMES OF THE SPEAKERS?
Can you mix the brand names of your speakers?
Well yes. Most of the time, new speakers are sold in pairs anyway. So say you had a pair of Pioneers in the front of your car and a pair of Infiniti's in the back, that is perfectly fine.
Now say you had a Pioneer in the left front door, and an Infiniti in the right front door. Since the speakers are most likely constructed differently and with different drivers, your sound would probably sound a little unballanced. Keep em in pairs and youll be fine.