Use Siri to Check Your Volume
First, you need to understand what your volume percentage is. Of course, you can check the volume level by pressing the physical buttons, but you can also ask Siri.
Just call for Siri and ask something like “what’s the volume,” or “how loud is it,” or just say “volume.” Siri will understand and tell you the percentage. If you’re almost at the max percentage and it still isn’t as loud as you think it should be, then you should move on to the other tips.