(1) The effect of cables -- as an improvement or conversely as a detriment-- to the audio performance in your rig is entirely system dependent .... full stop. There is no one-size-fits-all option.
(2) the effect(s) of cables as a potential improvement is an alchemy of ALL your cables together , Including the ICs and power cords. To parse out speaker cables by themselves as the potential definitive "silver bullet" is an incomplete or failed step.
(3) Without prejudice to the points above, and ignoring the simple fact that "jaw dropping improvement" is a highly biased anecdotal and personal value judgement at best ,; At either a $500 or capped $1,000 pricepoint, there are no "jaw dropping" improvements in available speaker cables, in the common sense general application of the term. I have never seen any product in this price strata that even approached a scintilla of that type of description. ... Improvement ..."yes". ....but "jaw-dropping".... never.
I have auditioned significant audio improvement by performing contenders , that are not subtle in the first part and certainly separate themselves from the pretenders (as a full ARRAY of IC, speaker, and power ) , but these were integral in crafting a system synergy in high-end audio systems with cable price-points to match in lock-step. Even these "high -end" cables would fail any long step approximation of "jaw-dropping" in the common sense term.
That term in terms of application to audio speaker cables is an audio unicorn proxy.
