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

sunnyjim
Auvio Square Parallel Premium 12 G speaker cable. $0.48/ft (no longer available?)
It's 99.95% O2 free copper, 50% of the strands are silver coated. 
It's not a "jaw dropping" improvement; but a solid one. Wish I could get more.
An 8’ long DIY stack of 3/8" wide .999 silver foil, each foil wrapped in Teflon tape, stacked, and drawn through an earth-grounded shield of tinned copper-braided tubing. About 1.5 lbs. of silver in all, at the commodity price of $750 plus a long afternoon of work.
@dgarretson .. what is the braided copper for? Is that one of your conductors​? Or are you dividing the ribbons into the pos and neg conductors and using the braided copper as a shield?
The latter: as a shield floated from the conductors. I soldered a wire to the braided copper sleeve and connected that wire to the ground pin in an AC outlet. Each conductor is in a separate sleeve.  Shielding improved upon the earlier unshielded version.
@toddverrone .. the whole project didn’t take much time at all. I used 16 gauge wire and 14 gauge jacketing. The wire threaded easily enough and just needed to be guided deliberately. Here’s a link to my blog post about the build where you’ll find a couple of links to exactly what & where I purchased the materials I used:

https://melvinsfoolishthings.blog/2017/03/20/loudspeaker-cables/