What cables can lower my forward treble.

I got the last bit of high end harshness and fatigue out of my system with super tweeters and some other tweaks.

The super tweeters were a loan from a friend but I never gave then back, mine are Golden Sound JSMR from Japan which are no longer made. There are others on the market which I couldn’t vouch for, but the thing I didn’t expect is that any harshness from my speakers was almost totally gone. I think (theory) is that the excess energy/ultra high frequency sound that we can’t hear is still present in the signal going through your speakers tweeter but isn’t reproduced and causes distortion, but the super tweeter is able to output the sound. 

The other thing that really helped and made things more smooth and analog sounding was Synergistic Research fuses. I was super skeptical, then I bought one for my amp and couldn’t believe what a difference they made, now they are in every component that has a fuse, they make things sound smoother and more analog and real.

The last tweek that also helped was buying a Schuman wave generator, there are tons on Amazon for like $10, but the ones I have are the Nobsound brand. They were $50 on Amazon and have a bamboo wood housing so they look nice. They don’t seem to sell them anymore but the brand is now Douk audio, no more wood case but similar product. Those really do make your room sound better by just plugging one in to the wall and setting it in your listening room, supposedly the best location is 5 feet above the floor in the front, I have one in front and one behind the seating position and they make everything smoother, and more analog. I even did some blind testing with my non audiophile cousin and she could even hear the difference turning it on and off.

It’s a really cheap tweak unless you buy the Acoustic Revive Japanese one that’s like $700 which may be better, I have some acoustic revive stuff and it’s really good.

All of the suggestions above will help.  There isn’t one silver bullet fix.

Is your AC power clean?     Do you have a dedicated circuit and/or a power conditioner?   If the HF from your CD player is hot, wait until you start streaming.

Over the years I have experienced different sound signatures with cable changes (and also my wife in blind evals) - even though the engineer in me initially dismissed the concept. Tried to smooth/tame the high frequency of Focals in the past while keeping resolution, and after extensive research and trials, found the Cardas Clear Reflection works (an amps ability to handle low impedance also matters).  I also now have SRF XL interconnects and power (nice cables) that I use with Cardas CR speaker wires. Check the Cardas website and viedos if your interested.