cable advices needed plz

[ares9245]

Hello, I bought yamaha 1065, MA BR5 as front, brfx for rears, and brw10 sub, br center.

I guess 2.5mm should be fine for the front and center. but I have a bit of problem for rears. Since I didn't plan it well I had to route cable along the corners of the room. one rear speaker will need 9 meters/30 feet cable and the other one need 13 meters/42 feet cable.
Do I need 3.5mm or 4mm for the rears then because of the length?

thanks a lot for any of your inputs.

 

[ben.bayliss]

2.5mm will be just fine for those lengths. You're still talking very short lengths in the big scheme of things.

 

[ares9245]

2.5mm will be just fine for those lengths. You're still talking very short lengths in the big scheme of things.

Ok, the salesman told me I have to use 4mm for the long distance, but i was skeptical.