Speaker cables to smoothen things up


I love the sound of my system. Its dynamic and neutral and very lively. However, my taste to music have melowed somewhat, and im prefer a smooth, relaxing sound at the moment and was wondering if a speaker cable change would smooth things up somewhat and reduce the hardness and attack from my system ( not bright, just hard)
My speaker cables at the moment are some synergistic research tesla quad. I got this for free from my brother therefore ive not tested other speaker cables.
Interconnects are tchernov reference cables and my subwoofer inteconnects are fat oval ic.

The chain goes as follow
Mac mini with audirvana - nad m51 - densen b200 -densen b330 - neat ultimatum mf5 and genesis g928 sub.

Was wondering if a speaker cable change would smoothen things up. Its not to reduce the brightness of my system, my system is pretty neutral. Just want to reduce some of the attack and dynamic off the system. If possible, not wanting to change the amp and speakers.

Ive heard about van denhuls to do this, and ive got a good deal for a d352 hybrid cables. Also a good deal for a kimber 8tc ( the older black and blue version). Would these help? Any reccomendations is much appreciated

Just for info, my room is almost fully treated. Big drapes and rugs and diffusers and bass traps all over.
nieveulv
Cardas Golden Cross, or probably any of the older Cardas cables like Neutral Reference will soften things up for sure.
Cables won't do it because they cannot overcome the fundamental sound that your components' circuits have. Sound lies in circuit and speaker design, not cables.
Nieveulv, I reread your post and if your system is too dynamic and "hard," then changing cables won't do much for you. Cables can be used to change the timbre or affect the soundstaging, but not to change the PRAT of a system.

So I'll agree with those who say a change in source or component is in order. Not familiar with your components, but as you know it's all about system synergy. Bojack has hit the nail on the head.