I am installing a pair of Wharfedale WH2 surrounds and need help deciding wire size. Does anyone think it adequate to use 18 awg for these small speakers @ 40'. Reason being, I want to run ulta flat wire (.05 mm)since I'm going to wallpaper room anyway. I know I can get larger sizes in reasonably flat wire, but prices go up exponentially in this real thin stuff. Would prefer not to throw away money if 18awg will do the job.