What speaker cable made a major difference in the sound quality of your speakers??

I am curious what speaker cables made a big "jaw dropping difference" in the sound quality of your current speakers.  What most impressed you about the difference;  that is, overall musicality, tighter, deeper bass, midrange clarity and soundstage depth, etc.etc. 

Keep the price of the speaker cables chosen or auditioned at  between $800- $1000 or  from  $1000-$1500. Was the cable bought new or used??

  Thank you,   SJ

I never believed the cable thing for years. then a friend of mine who owns an audio shop was trying out the Siltech line and asked me to give a few of the models a try I ended up buying the FT12 silver ribbon and I became a believer.. Dam it ! I've had them for years now very happy tried others and never thought to upgrade or side grade whatever. I like the Siltech silver/gold wires.
Canare 4s8. Balanced, dynamic,  detailed, superb extension on both ends of the audio band.  It lets your amp have the best grip on your speakers.  Feels more powerful, punchier than cables twice as big. Details and harmonics come through like you would not believe... for less than $20 a 10ft pair, it is superb, and approved by many audiophiles as it has been sold throughout the years wrapped up under different brand names, at much much higher prices of course.

1984 MIT Music Hose that I am still using along with 1984 MIT interconnects.   I often wonder, should I try any of the current gen wires and which ones?  I paid $10 a foot for the Music Hose in 84. Today's prices just blow my mind.   I should have invested in copper.....
ASI Liveline, bought new from dealer and 2 pairs for TRUE bi-wiring. It's replaced Synergistic Apex ~7+ years ago. Also using a full loom of ASI Liveline ICs.  It works equally well with both SS and tube components.
Audio art cables will make a significant difference. I no longer use anything else.