How new are your speakers. Brand new?. 300 hours let the bass drivers break in a bit. Add a little deeper quicker response. Where are you at on hours OP?
A Good OCC/teflon weave 16 strand (NO silver clad) will sure help. 125-200.00 usd for a pair. Or buy your own and terminate. I'm listening to a pair right now I paid 150.00 for the pair 3 meters long. I cooked them for 14 days. Perfect with planars and ribbons.. I'm cooking 2 pairs of ribbons, they are silver clad. I cook them for over a month, then 3-500 hours of playing. Best I ever heard for 200.00 a pair.
2. Lamp cord it's a real close second.. :-)
3. Purist
4. Odin
5. ESP, that is pretty warm too. LOL
Cable is not a tone control, ok, sure can be though. I use tone control for a reason. I have a way of getting where I want to be. Sure not with a Line pre amp though. YUK. I've had a few too. Their in the pile somewhere. VTL, CJ, Dodd, Krell. SST I wound up using a Manley tube super EQ. I went back to tone control every time.
I like to many kinds of music you have to have a way to EQ. Leaves way to much music out. Indian music and a lot of the South American and Caribbean music..
Jazz, Rock and Roll, and Country, there is just a tad more out there. Me singing in the shower, too. :-)