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
It sounds like you're using your Oppo as a preamp which could contribute to the sound you hear. Also, depending on the length of your speaker wires - assuming ~8' and not longer, you may have better luck looking for "warmer" interconnects to tweak your sound. Just as an aside, I think putting a tube preamp between the Oppo and your Belles will transform your system for better.
gunmetalzin,

I had the early nineties Monster "Powerline 2" speaker cable for some time.  If that's what you have it's Nasty Stuff.  I suggest the Acoustic Zen Satori I use (of course).  It can be easily found used at your price point.  It clears out the glare and edge in a huge way.  There is a slight lower-mid / upper-bass bump that can be pleasing in the right (not overly warm) system.  
It's unlikely to be the Ryan or the Belles.  Very unlikely.  Obviously, principal suspicion falls on the Monster, though the situation might not be ameliorated by the Oppo.  I think you should rewire the whole loom, interconnects and speaker.  Make sure you stick with all copper (+ if relevant, gold plating).  Some good recommendations here; you might look too at Wireworld and Audio Sensibility.
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As much as I eschew disagreement I feel obliged to say ferrites on audio related cables only hurt the sound, except in very limited cases. However ferrites, the nice big kind, do quiet nicely on appliance power cords.