Biwiring B&W Matrix 802 III with Kimber 8TC & 4TC

Is it a good idea to biwire my B&W Matrix 802 III with Kimber 8TC (low) & 4TC (mid-range & high).

I'm using single runs of 8TC right now. I thought that adding a ma 4TC cable for the mid+ tweeter I can improve the ambient resulution, but I'm worried it may make the system sound brighter (especially since the mid-drever will also be fed by the 4TC strand).

Any advice
I would sell the 8TC and buy a better wire (like AZ Satori) and run it single for about the same money as the 2 you mention, which are a little thin sounding for my tastes.
For my 801 Matrix I used A/truth Agent ( mid -top ) and Midnight+ ( lows ). Worked very well.Not all that expensive either...
As an option, you can buy some Canare StarQuad 4S11 for 69 cents a foot from Markertech and experiment with bi-wiring. Won't cost you much, and you should have a pretty good idea if bi-wiring makes the improvement you're seeking.
I am currently biwring B&W Matrix 802 III speakers with Kimber 8TC(low) and 4TC(mid/hi) and I like the sound.
I previously biwired low and mid/hi with 8TC but I like the 8TC/4TC combination better. It is less bright than all 8TC and the bass seems a bit more prominent.
I once had the B&W's single-wired with 8TC, but that was several years ago. As I remember, moving to biwiring was a significant improvement.