According to the supplier : Vogels VLB-500 is not suitable for Samsung HW-Q950T speakers surround speakers. The wall mounts VLB-500 are only loadable up to max 5,0Kg. We have not found any information on whether the surround speakers are equipped with a screw thread at the bottom or at the rear.

Please have a look at the manual to see which screws come with the product. I'd say your Samsung speakers have 1/4" screw holes (diameter), imperial screw type (not metric). So it should work.
https://brandportal.vogels.com/m...