simple question

["oliver" <sumton@sbcglobal.net>]

this seems obvious, but i don't want to blow oops i mean destroy my horns:

if i want to test my horns, can i hook them up one at a time to a battery 
and they will either work/don't work or is that too much juice and i need to 
put a rheostat in the middle?  or can i hook both horns up in 
sequence/series directly to a battery?

thanks in advance!