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'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.
The cheapest form of HF hash attenuation is to add on ferrite on the RCA from the source. AQ makes a variety of them or try Amazon type in "Ferrite noise suppressor" Plenty of sets, ones with a variety of sizes around $12.
You place one (or 2 or even 3) on the RCA wires from your digital source. They cut the HF grunge to a degree. and may be ALL YOU NEED.
Add one to the source AC cord too.
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. 
Room acoustics and speaker placement are the first places to go looking. If the speakers sound great 2' away, but harsh by the time you are sitting down, this is why.

Bare floors, and reflections between and behind the speakers can also make this happen.

Otherwise, strongly recommend mid-range Wireworld as good ways to soften up highs.

Best,
E
Sorry to disagree Geoff, I used ferrites for years on a variety of CD player RCA output wires to good effect. I have no problem recommending them to someone searching for a way to cut HF garbage from the speakers due to digital grunge... when they are looking for a low cost solution. The fact is $12 to discover if it is a worthwhile TRADEOFF in their system is DIRT CHEAP and may be all the need.Plus, as you mention, the ferrite may be good 'anyway' on AC cord.