ELK-SP12F minimum wiring

Greetings,
 
What is the minimum wire required?  Something tells me it's 18/2?  But can I use some surplus 22/4 drops by doubling up the pairs???
 
I would end up with 4 of these speaker locations, thanks.
 

18/2, especially connected to any sort of device that pushes any wattage.
 
Doubling up conductors is a poor practice.

All righty then...22/4 will be limited to motion sensors, magnetic contacts, etc.  I've got the 18/2 drops available but thought I'd ask,  thanks for the response.