TOA Canada - What is the maximum length of speaker wire for a 70 Volt line?
Ask Dr. A! Does Speaker Cable Gauge Matter? | Audioholics
A practical guide to speaker cables
18AWG Speaker Wire, GearIT Pro Series 18 AWG Gauge Speaker Wire Cable (100 Feet / 30.48 Meters) Great Use for Home Theater Speakers and Car Speakers Black : Amazon.co.uk: Electronics & Photo