Another idea that may or may not help: Ferrite cylinders that clip around your cables. Don't know for sure how much dynamic damping they cause. A pricey alternative to consider would be Z Sleeves by Z Cable. Here's a link to those:
Z Sleeves by Z Cable
I've never used them, only heard of them. Good luck and don't give up yet.
-Bill
Z Sleeves by Z Cable
I've never used them, only heard of them. Good luck and don't give up yet.
-Bill