Where is the foam cushioned decoupling brackets, this is a flawed system. The sound insulation will not work in this instance.

For RCs there is a path to transmit vibrations through the screw contact area but it's very small, here the horizontal cuts make the "decoupling", which still do a nice job, even if not so well as RCs, they are better suited for all types of ceilings, especially for standard heights in apartment blocks where the height is at 100inches or 2.5m. Obviously, you cannot afford to lose 20 inches or 50cm from this height. There is nothing more nerve-braking than to see how all youtube videos present wooden joists, with wide and deep empty spaces, just good to be filled up with fiber-glass insulation, as if the basement ceiling is the same as the roof. Well, this may be the case only in US, and even there, I'm pretty sure there are many brick buildings, with concrete floors, no wood unless in the country side. Still, all youtube videos which are clearly ads for their own companies show these annoying wooden joists, which I've seen only in vacation and only when going into the mountains, other than this all my acquaintances live either in brick houses with concrete ceilings, or in concrete apartments blocks with -obviously, concrete ceilings. While you may say, well if it's from concrete it's already soundproof, it's not the case for 5" concrete, you can hear all the steps and all conversations even if not understanding what they are talking about. Your companies will never be successful until you have the courage to tackle the apartment blocks and brick houses with concrete ceilings which -if from 2nd half of 20 century will have lower ceilings, so they can afford to lose maximum 1.5-2 inches.

It’s not a proper isolation. The real slab is not decoupled from the isolation