In my opinion and experience shielded speaker cables restrict dynamics! My speaker cables are DIY, the positive and negative are tightly twisted together, no shielding and very short @ 12'' long. Cable material consist of,12 AWG Orange and black Mil-Spec M22759/11 (PTFE) Stranded Silver Plated copper, they look similar to this when finished. Both amp and speaker ends are bare wire. For in the what it's worth category, short speaker cables helps to minimize EMI interference, also try to keep power cords away from speaker cables. 😎
Mike