Need recommendations on 15ft speaker cables

I am currently using blue jean Rca cables which are all copper 10awg I believe.

I cannot find "Blue Jean Rca cables" listed as a speaker cable on their website. If those cables are in fact an all copper, 10 awg speaker cable, then they should be sufficient for your B&W 805 speakers, assuming a 15-foot length and a competently powered amplifier. What are you trying to change or improve?

Ok, then same question, "What are you trying to change or improve?"

There is nothing inherently bad about 10 awg stranded copper speaker cables.  Since you are looking for cables that "provide SQ upgrade," is there something about the sound that you don't like, or that you hope would change with different cables?  Otherwise, you are going to get a bunch of brand name cables recommended by a variety of posters here.  At that point, if you are curious, your options become buying and trying different cables or maybe looking into the lending library at The Cable Company and then you can figure out if something sounds better in your system.  Let us know how it works out.

The OP is already using 10 awg stranded copper speaker cables, which is plenty big for the run length.  Other than a few posters suggesting Canare 4S11, just about every poster has given a different cable recommendation.  BTW, 4S11 is actually a smaller stranded copper speaker cable than what the OP is using now, at 11 awg when configured in star-quad geometry.  

At this point, he/she either jumps on the buy/try cable merry go-round or tries the Cable Company or others that will lend cables in order to evaluate which of many cable offerings he/she likes best, or if they even hear a reliable difference between cables.  A lot of us have done the buy/try route, but it is expensive and time-consuming.