When iPhones send audio to headphones, the system stops you from increasing the volume level above a certain threshold - and that's a good thing.
After all, no one wants to ruin their hearing.
But if, for some reason, the music is just too quiet on a paired Bluetooth speaker or in the car, for the longest time there was nothing you could do about it.
As of iOS 14.4, however, Apple has made a significant change to its limitations to prevent hearing damage.
In the Bluetooth settings, you can freely define what kind of audio device each paired device is. And that means if you've paired a speaker or car stereo here, then your music can be turned up louder.
Apple has sinced upgraded iPhones with another minor software update (iOS 14.5), adding several new features including AirTags support and more controls over how apps track you for marketing purposes. You'll generally receive an automatic message that the update is available. Then all you have to do is tap on "Install now". – dpa