I think both can be effective but if you watch with a full crowd first weekend to me thats the best atmosphere for horror + comedies.
I know myself I turn phones off and eliminates distractions and if I really want to get into it and Im alone I wear my surround sound headphones.
I have sony pulse elites that are 7.1 surround sound and they have a custom eq for horror films and you can even have them vibrate during heavy bass/jump scare moments.
And if I go see a horror film in theatre its only with certain people. If you go with loud people that like to talk or crack jokes it takes you out of it and you don't take the film serious.
Even though horror is my favorite genre,a lot of films are,well,shyt and you kind of have to dig through the garbage sometimes.
But when you discover a film that clicks with you and gets under your skin theirs nothing like it.
I can't wait for horror in VR and horror games in VR.