Hi @kayoti, thank you for reaching out to the Sonos community. I appreciate you for bringing this concern to us. Let me help you out.

I understand that you want the Sub to have separate level settings to adjust the bass, treble, balance, and loudness. This feature is not available. What I can do is send in a feature request to make this available in the Sonos app. We don't have the timeline and the information to share with you about this but you can check our announcements when this feature becomes available. 

If you need help with any other information, feel free to reach out. We and the community are always here to help.

I also would value this feature 

Yes, please.

Absolutely!  Very annoying having to reset every time I toggle between music and TV

Do other manufacturers offer this?

I notice that my kids will tune their Spotify with higher bass levels and then stream from the Spotify app, keeping those higher levels. In this case there’s nothing Sonos can do about the bass....

There isn’t anything Sonos can do about Spotify’s audio settings, but Sonos has full control over the audio settings within its app. The ability to set different EQ settings for TV and Music shouldn’t be too difficult. We can already set different audio settings for the surrounds for TV and Music which means Sonos can auto detect whether the source is TV or Music which means it should be able to automatically adjust to different EQ settings too.

This is an absolute must have! The sooner the better. I actually expected this to be a standard feature when buying my sonos set… Bit disappointed it isn’t (yet).