Is there a way to change notication sound volume on Marshmallow / Nexus 6P?

[AC Question]

Settings seem to allow changes to Media / Alarm and ring volumes but no notification setting. If one changes ring volume then it seems to adjust notification volume too but I would like to reduce notification vol while leaving ring vol high.

 

[hallux]

I believe ring and notification volume are linked, no way to adjust one without the other.