OK Bruce - just took a look at your system and based on those components, upgrading speaker cables may well reveal details currently unheard.
But - If it were me I would probably opt for a different brand.
Here's my thinking - you are already using a 9 gauge cable that uses good quality copper with low resistance - moving up to the 8 gauge 12tc would probably result in only subtle improvements in detail and dynamics
Significantly improving on your systems current performance would probably require a change in materials and design used in the cable's construction
e.g. maybe a cable that introduces silver coating or a silver/copper alloy and/or a significantly larger diameter cable.
That would be the direction I would proceed.
Hope that answers your question.
Good luck with the search
BTW - what power cable do you use :-)
But - If it were me I would probably opt for a different brand.
Here's my thinking - you are already using a 9 gauge cable that uses good quality copper with low resistance - moving up to the 8 gauge 12tc would probably result in only subtle improvements in detail and dynamics
Significantly improving on your systems current performance would probably require a change in materials and design used in the cable's construction
e.g. maybe a cable that introduces silver coating or a silver/copper alloy and/or a significantly larger diameter cable.
That would be the direction I would proceed.
Hope that answers your question.
Good luck with the search
BTW - what power cable do you use :-)