Yeah.....I forgot. You are in AU. You really don't have access to Part Express's DAYTON ND20TB-4 REAR-MOUNT 3/4" NEODYMIUM DOME TWEETER for $4.10 US$. see: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=275-035
Shipping would eat you alive. If you had had that access, would you have chosen them over the horn tweeter, or would you have purchased as horn of similar value($61 US$)? Having just done the same I chose the 15 tweeters over the $61 horn.