I only meant that factory units have more power because they have to push a more resistive factory speaker . But not that they have more power for volume or clarity . I have a 500 watt Monsoon system in my TA and it is driving 10 ohm factory speakers , If I replace them with 4 ohm speakers , the effective power would be around 1200 watts by power to resistance ratio. But that is just an estimate. That is the only reason I said they are more powerful , because they have to work harder with factory speakers . Rob