All iOS audio suddenly really soft?

It wasn’t doing this in my previous build, I’m not sure what happened.

The sounds are all of around the same level and are 2D, volume is maxed on everything. In unity they’re of an appropriate sound level, but on the device build they’re super soft (even with the device volume all the way up). Not sure what could be going on. Any thoughts?

As someone who specialises in audio production my guess would be that the volume reduction your experiencing is part of the Apple device itself, Apple have decided to implement a kind of “Limiting” across their products range

---- Master for Sound Check and Other Volume Controlling Technology

Sound Check is a feature in iTunes and all iOS devices that lets listeners hear all their songs at approximately the same volume. It first determines the loudness of a track and then stores that information in the file’s metadata. (Songs downloaded from the iTunes Store already contain this information.) The metadata is then used to raise or lower the volume of each track to prevent jarring volume changes while a device is shuffling songs.

The effect of Sound Check, as well as other volume-controlling technologies, is that songs that have been mastered to be too loud will be played back at a lower volume, ----

More Information can be found at the following

https://www.izotope.com/en/community/blog/tips-tutorials/2014/06/mastering-for-compressed-audio-formats/