Do I Need a Siren Driver for Ademco Vista 15P

["rahouston@xxxxxxxxxxx" <rahouston@xxxxxxxxx>]

I'm installing an Ademco Vista 15P panel in place of an old Napco
system.  The Napco unit had a built-in siren driver, which was
connected to a couple of speakers in the house.  It looks like the
Ademco doesn't have speaker drivers, as best as I can tell.  My options
appear to be either to get a separate siren driver or replace the
speakers with Ademco (or equivalent)sirens.  Is this correct, or am I
missing something?

Thanks for your advice,

Rob Houston