When you check your voltages, check when the car is off First and then when it is running. Could be a bad diode in your alternator. A bad diode will often times cause the alternator to show a lower voltage while running at idle(warmed up), than when the car is off. However when you rev your rpms, voltages almost become normal. And in your video, was that when you hooked up your ipod direct to the amp? because it sounded like you were asking someone to turn it up from the head unit.