Erik suggested WireWorld Eclipse interconnect/speaker cables. These are good to help calm down things, but only if you get the "copper only" cables.
In addition, get some basic level copper-only gold-plated Audioquest power cords. The combination of their copper-only solid core conductors and gold-plated plugs will really help calm down the harshness and highs. It will also smooth out the sound compared to stranded power cords.
In addition, get some basic level copper-only gold-plated Audioquest power cords. The combination of their copper-only solid core conductors and gold-plated plugs will really help calm down the harshness and highs. It will also smooth out the sound compared to stranded power cords.