Default [Q] Bluetooth Audio Volume

Is there a way to increase the volume on bt-headsets?
if i set the volume on the headset to 100% and the volume on the watch to 100% it is still not really loud.
Current devices:
Asus Padfone 2
Nexus 7 2013
Omate TrueSmart 1/8 2100

Waiting for:
Neptune Pine
AI-Watch