Battery-Powered Audio System Buzzing?

@immatthewj I am trying this setup with both my upstairs and downstairs systems, the difference being the downstairs setup has the Schiit Aegir going into Tekton Impact monitors. For the downstairs setup, yes it is a dramatic improvement. The sounds was great to begin with, but on battery there is a wider soundstage, more holographic presentation and for lack of a more clinical term - an intoxicating musicality. On the upstairs system with the Tyrs and the Encore towers the difference is harder to tell. Now that I have it setup on battery I will try A-B ing between battery and wall-power to listen more critically for differences. 

While I appreciate the other suggestions, this experiment is already into as deep technical waters as I feel comfortable wading through.

And yes, originally when I posted I still had 2 subs and the DAC going through wall power. Once I put everything on the battery the buzz disappeared.

Glad I could help.  :) 

As far as I remember these issues arise due to the generator neutral and the house neutral not being bonded to the same reference point setting up a neutral/ground differential which causes current flow through the ground... or something like that.  At least this will point you in the right direction of explaining why. 

The solution besides putting everything on the battery would be to use transformer based isolators to anything not on the battery. 

@sid-hoff-frenchman I'm not sure if I'm tracking. Are you testing or horsing around with the battery? Or will you be integrating with your system for mid-term or long-term use? If it's a mid- or long-term route, I would advise against taking that road. No matter what benefit or perceived benefit  you are getting from using it, forgo it. There may be unknown or unseen risks that could emerge later, potentially damaging your audio gear. I'm sure the designers of battery manufacturers do not have home audio gear in mind.  Based on my experiences and observations, even the most well-planned designs and tested products can still fail at some point. Nuclear power plants, aircraft, vehicles, motors, and batteries are good examples.