Why are my trips like this?

I recently bought and tested 4 dmt carts and have been experimenting with them. I noticed my trips will be completely random like i’ll see strangers.. people i’ve never seen before, along with no geometry or anything. i’ll see these people or objects clear as day and my vision will constantly be moving almost as if i’m in an old slideshow movie. on there other hand, sometimes i’ll see a vast amount of amazing visuals and geometry but these trips come with an overwhelming ringing and mental noise throughout the trip. i never see any entities or can never interact with them, i just see random people a lot of the time. why would this be?