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
rrwolfgram,

My silver wires also blew away every brand name I have ever had. Thanks very much for this link.
I put together some .999 silver loudspeaker cables a few months ago using info from the website @rrwolfgram mentioned and couldn't be happier with the results. Total cost for an 8' pair was just shy of $200. 
Audio Note SPx silver Litz, one of the few components I doubt I will ever replace.  The retail price is very expensive but I managed to buy mine as a demo from an Audio Note dealer within your budget.
I have to agree with @grannyring . The Duelund 16GA tinned copper is an absolute giant killer. It smashed my $3000 Argento's. 
At $10 a meter, it's a no brainer.