Still Need Help

Try to isolate the subs on their own base that decouples them from the floor to remove the floor excitement they are creating. A good way to do this is to use a slab of stone under the subs. It is effective and relatively cheap and painless to implement.

Can you be more specific? What do you mean “vibration”? Is the sub output vibrating/energizing the room enough to effect the TT during playback, or are you getting woofer subsonics when the stylus hits the vinyl? Two different problems. 

Try plug the ports of subwoofer?

Your Rega wall support is made from hollow metal that can resonate. Putting P3 directly on it will not help alone. You need to decouple somehow your tt from the shelf. And still airborne vibrations would affect its lightweight chassis. Try to have the lid removed when listening.
G

Wall mounts generally don't work all that well. To isolate a turntable from low frequencies you need a **non-resonant** mass beneath the turntable; to which the turntable is coupled with points.

You use points to couple, so as to allow vibration to move from one object to another (where hopefully it is damped). You use squishies to isolate, to prevent vibration from moving from one object to another. So you don't use squishies between a turntable and platform because airborne vibration occurring in the turntable isn't treated.


If the platform is in a stand, it should be isolated from the stand by squishies, like these:
https://www.isolateit.com/hemispheres.html
The stand will sit on the floor of course but if you can mount it on a set of bearings the turntable will be more unassailable and also more impervious to foot falls. These will work although you might have to do a bit of fiddling:

https://www.symposiumusa.com/rbjr.html
Good Luck.