You pick up your phone, connect your Bluetooth speaker, blast the volume to maximum and start dancing around the house like no one is watching. A couple of hours later, you're headed out to walk the dog so you grab your Bluetooth earbuds, connect them to your phone and the music explodes in your ears at the same high level. This should not be the case. Every accessory you connect should retain its own volume setting so that you don't get deaf when you first connect a headphone or speaker. Until now, Android hasn't done this right but it looks like P will finally fix it for us.

"Implement Bluetooth device volume memory" has been approved and merged in the Android Gerrit, so it should roll with one of the upcoming Developer Previews. When it's live, Android will remember your last volume level for each Bluetooth device and use that. So if you blast music on your headphones but prefer calmer volumes on your speaker, or the other way around, the setting will be retained for each of the two, even if you switch back and forth between them. This is another addition to all the volume (including Bluetooth) improvements that Android P has already implemented.

Source: Android Open Source Project

Via: XDA Developers