For that horn an ampli with a minimum of 500W. For the ampli buy a set with 12 "80W speakers. 10" media and dome or piezo twitters. And ready.
You have to check why the FAN does not turn. Check the voltage you may already need a new one.
The fan adapted a 12-volt source, because it was good, it only seems that k did not get any current, but it stopped again, it sure burned, I didn't check it