Head unit pre-out to sub?

[SKNOT9]

Hi there. i have a sony head unit with a subwoofer preout. i was wondering if this is amplified? can i run it straight to a subwoofer or do i need an amp? any help would be greatly appreciated.

[calais_cruzin]

You have to run the RCA's to a amp.

You cant run a sub off that, its what sends the signal to the amp to power the sub