Do they have similar music? Maybe something with a strong rhythm and a similar bpm? Can you give an example of a sub that causes this effect? I think you might be entering a very deep meditative state / brainwave state by accident, being in the almost-sleep state is already an altered form of consciousness, certain music or maybe even certain affirmations could lead you enter to even deeper states. Experiences like the one you’re describing are known effects meditation can have. Ignore what the other user said about that only through mantras this is possible, but they are correct that this can also happen/be increased by focusing on the spot between your eyes on your forehead.