Welcome to AC.
Contrary to a lot of popular belief you see posted around the internet, IMO, once you reach the level of something like a SS8 (direct priced at 8-9K, if sold at retail 15-20K), your system needs to be run like a highly precise, tight tolerance, well oiled machine. Said another way, the adage that speakers are "some large percent of the sound you hear," becomes less truthful. A well designed transducer, should transduce, and add minimal of its own signature to the sound. It will sound like, what it is being fed.
Given that the SS8's, and many other designs on its level, are so revealing, something wrong in the chain is going to be horrendously notable.
I am experiencing something similar with my Exotica 3s, when I use my PC as a transport. The sound falls apart, and becomes thin, harsh, and muffled. A stark contrast to using another transport, with the same DAC.
All things become evident with enough clarity. Noise, EMF, RFI, distortion, etc, etc, can ruin your sound.
My point is, the issue might not be your speakers, so much as something else in the chain.
Yes, you might like the Dynaudio better, but its a significantly less revealing speaker. The solution to your problem might not best be solved by "covering" up a problem potentially caused by something else.
Room treatments, power conditioning, more careful equipment synergy, different sources, cabling, tweaks like footers, etc, etc, can all help inch your closer to a more desirable sound.
Hardness and harshness to me sounds like two potential issues if I had to guess.
1, is acoustic issues. Do you have treatments at first reflection points? If not, try blankets and see if the condition improves. If so, consider some GIK panels for reasonable pricing. They also sell Art panels if WAF is an issue.
2, is a power issue. In my house, without power conditioning, the sound is atrocious. Thin, hard, unfocused. Even my Merrill monoblocks sound better into my power conditioner. Check PI audio. Magikbuss is a cost effective reasonable first step.
If you already are employing these strategies, then something else is a miss. Perhaps your transport/source, or cabling.
Any movement towards a speaker that functions on the same level as the SS8, will only likely reveal the same issues, since I would think its something else in your system.
What is the rest of your system?
Good luck. Don't be afraid to experiment. There are cheap options to try first, before you dive in with both feet.