One has to pay attention to cable gauge, length of cable, power output of amp and speaker efficiency when determining single or double runs of Clear Day speaker cables.
I found out that the 16 gauge Tempo Electric speaker cables were fine with my Tonian Labs TL-D1s but they imparted a hooded effect to the highs and fattened the mids and bass, giving it wooly quality when paired with my new Clearwave Duets. They are high purity silver as well.
Going back to my Clear Day single run speaker cables (24 gauge?) was a match made in heaven. I remember trying out both the single and shotgun (double run) of the Clear Days and the shotgun version imparted that same hooded and fattening quality so care needs to be taken as what works for one set up won't necessarily work in another. Both the Tempo Electric and Clear Days are 8' lengths.
Just my two cents worth, for what it's worth, since it only cost me two cents.
All the best,
Nonoise