There is no way no one is hearing this rattling/crackling sound on the 15 lineup when above a certain volume level on some sound frequencies. Just went to an Apple Store and all iPhone 15s had it. The pro/pro max and regular/plus ones. I have it on my 15PM. Check this video for a comparison to an iPhone 14. It’s definitely a widespread issue, I guess, since more than 10 devices at the store had the exact same problem.
My wife’s 14 pro max and 12 had this issue and both times Apple swapped with no issues at the store.
I’ve always thought it was an issue with iPhones with their speakers being easily popped.
Apple should be fine if there’s an issue. Take it in ask if there’s an issue with it and see if they need to swap it for a new one :)
I went to an Apple Store and they ran diagnostics on my phone and said there is nothing wrong with it 🫤. What’s bizarre to me is that all iPhones at this store had this exact issue, which means it can’t be only my unit.