With all that you are doing to improve performace I would suggest using
high purity audio grade thru the wall cable .
Since Cardas no longer makes it you might look into JPS .
Size: 10 AWG, UL/CSA listed for in-wall use
Design: Optimized Field Matrix (OFM) construction
Price: $18 per foot
Company Information
JPS Lbs
4893 Transit Road
Suite 150
Depew, NY 14043
Voice: (716) 656-0810
Fax: (716) 656-0811
E-mail: info@jpslabs.com
Website: www.jpslabs.com