I am looking to install new cables for my surround setup 5.1 4 and would like some advice. I see that van damme blue is highly recommended and I also read a brief review on another forum that the clear van damme cable the LCOFC was even better. My longest run is about 20m will 2.5mm be good enough for this distance or do I need to use 4mm? Is the LCOFC better than the blue? Do I need to use different cables for my front L/C/R to my Atmos and rear surrounds? A retailer suggested that I should use different ie higher rated cables for the front, especially as the speakers I want to use have a ribbon tweeter.