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
Since you have Synergistic speaker cables why not try another product of theirs XOT transducers. You can try them for free for 2 weeks. You get a full refund if they do not do the trick. Easy to install and remove. Cheaper than a lot of new cables-$399.00.
Good luck Pete
Spatial Audio Quantum Field speaker cables and/or pair of their VB1's should do the trick.
I don't have much experience with speaker cable experimentation but I've tried numerous interconnects and power cords over the last few years. My system was very dynamic with a pair of Fusion Audio Enchanter power cords and a Virtual Dynamics Platinum Nite pc. The interconnect was a Granite Audio 470. Speaker cables were DIY copper wires from Polar Cables. Dynamics could be absolutely jarring. I wasn't quite satisfied though with the precision of image outlines and there was a slight bit of midrange brightness so I worked some other cables into the mix. I found the Sonoran Audio Plateau interconnects to soften things up a bit, reducing bass slam well into the lower midrange and a pair of 6Sons Audio Windigo power cords improved imaging and detail while softening dynamics. This wasn't what I was looking for but it may well help you. Good luck.
Agree on Cardas...would also suggest for the money to try some older Transp Reference cables...you can find them here for cents on the dollar. I would go back to 10 year old cable...the reference level or above. There was Reference, Reference XL to start with. Very smooth, dark backgrounds...in fact some say they were designed when the original Wilson X1 series was still around...and being quite scientific in the treble, the combination with Transp Ref worked quite well.