recommendation for speaker wire to soften the highs if possible


Hello,
I need help. My problem is my system sounds harsh on the highs to me. Not extremely bad, but enough that I need to fix it. My system consists of Ryan 610's, oppo Sonica Dac, and a Belles 150a hotrod amp. Speaker wires being used are old monster cable from the 90's. I also have monster cable rca. I mostly stream through Tidal. My question is can I make the desired effect by switching cables or should I add  a tube amp or pre amp. My budget on the wire would be around 300.00
Thanks in advance for any suggestions
128x128gunmetalzin
I suggest thinking of your audio system as a whole. Something is causing harshness. There are two ways to treat that.

First, as Elizabeth suggested, attenuate the offending HF with ferrite beads. Cheap, easy, and probably effective, unless your speakers are the offending component.

Second, find the source of the harshness and fix it, usually by replacing something. Ultimately that will give better sound, and so I do it - but that's because the bug bites me daily. Warning: it's time consuming and costly, because it could be source, amplification, speaker, room.

To test the speaker cable hypothesis, do as noromance suggested.
ieales has some good suggestions too. Lots of soft things in the room, like carpets, can help.
I agree that Dueland cable might tame the harshness you are hearing.  I don't see a preamp in your system, and if you are on a tight budget, I  would heartily advocate hearing a Schiit Freya preamp with the tubes upgraded to Shaguan 6SN7 tubes and you will get taste of audio splendor.  The next and final step would be a Don Sachs preamp. :-) Consider room treatments as well.  
Get Granny to make a Dueland set and jumpers. You will not regret it!
Thanks for all the great advice. I do have carpet in the room and my monster cables are Powerline plus 3. I also have my amp and oppo plugged into panamax MR4300.My speakers are 8 feet apart and on stands at 26 inch. They are about a foot away from the wall. I have furniture in the room as well. The room and my wife :) limit an ideal setup. it sounds like this weekend I should move things around to see if it makes a difference. If it does not make a big difference I think these are the suggestions if I’m reading correctly.
  1. .Replace wires with Dueland wires, or Signalcable or supra wires.
  2. .Replace interconnect cables.
  3. . Have Grannyring’s build some wires
  4. . Down the road add a pre amp (schiit or other tube)
  5. . * Ask local dealer to loan out and try cables. I like this option and I like the local dealer but price differs greatly.
Thanks again for all the help