Which app are you using? The Studios should be plenty loud enough to cause hearing loss.
Always check the empiendence of headphones before you go plugging them in ipads and phones.If all headphones sound quiet then look for a pre amp app or music player. Loads on android, no idea on ios though.
none at the moment, using Spotify for my source.
Crap ipad or crap headphones then mate. Way too many headphones have to meet regulations so idiots don't wear headphones loud and damage thier ears. Ergo they by default don't go all that loud. I always check or test before purchasing, although in covid times that's almost impossible.
It’s via Bluetooth