Unlink Bluetooth and system volume - nougat

I have just upgraded OP3 to nougat.
One feature of nougat I dont like is :linking system and Bluetooth volume.
Please give a solution to unlink both volumes. So that I can change both volumes separately either one from Bluetooth headset and one from system. Or both from system.

Reason I want: I want my Bluetooth device volume to highest level. This gives me bass sound more.
And if I increase volume now from Bluetooth headset or from android system (mobile) both volume increases and shows as single volume on screen. Keeping volume to highest level gives me too much volume. I want more bass at less volume. Which can be possible if I keep bluetooth headset volume high. And system volume low/medium(adjustable).

Please can some one resolve this. This feature (a problem for me) depreciate my music listening experience.