I want a portable 120v power source
I wish to power an Ikea Eneby 30 speaker
I read that it draws 40W, I don't think I have the means to test that
There are $100-$200 units readily available, and I might ultimately go that route, but this seems like it could be a fun project.

If I could insulate/protect everything, do you suppose I could just hack apart a cheap car inverter and connect it to a SLA battery?

I might grab a SLA charger and wire up a double-pole double-throw switch so the battery can only be connected to input or output and not both.

Going to keep researching, please point out any glaring retardation or areas for improvement.
Thanks, have a blessed day