Hi, I have searched for a specific answer but can’t seem to find it. I have a Sonos Connect Amp currently driving 2 third party speakers. I’d like to add an outdoor subwoofer, which seems to be passive. The solution I have seen is to add a separate amp for the sub. 

My question is, at what volume should the sub amp be set? I definitely like to vary the outdoor volume for the regular speakers depending on the situation (through the Sonos app), but don’t want to have to manually adjust the sub. 
 

Is it possible to automate the sub volume adjustment?