Seconding a point that was made earlier in the thread by Nick_sr, the degree to which cables will make a difference depends not only on the intrinsic characteristics and quality of the cable, and on the quality and musical resolution of the system, but perhaps just as significantly or even more so on interactions between the technical characteristics of the cable and those of what it is connecting. Impedances, for instance, among many other dependencies that could be cited which have no direct relation to the sonic quality of the system.
See my post dated 12-15-12
here for a summary of many of those interactions and dependencies. That post also describes a couple of examples of how a given cable can sometimes even have exactly opposite sonic effects depending on what it is connecting.
It should therefore be kept in mind that the ability of a system to resolve musical detail, and its ability to resolve differences between cables, are two different things. And sometimes there may even be an inverse relationship between the two.
Finally, it should be kept in mind that the sonic effects of line-level analog interconnects and speaker cables will be proportional to their length. A reduction in length will bring the performance of those cables closer to neutrality (i.e., closer to having no sonic effects), everything else being equal. That is not necessarily the case, though, with digital cables, phono cables, and power cords, due to the complexity and/or unpredictability of the interactions that are involved.
Regards,
-- Al