I feel you. I'm sure there are multiple ways to make this work but if it were me, I would probably use the cords/adapters below. Here are a couple examples of the cords I'm talking about.
Splitter- https://www.amazon.com/ONXE-Headphone-Splitter-Adapter-Speakers/dp/B073BKCB3W
Adapter- https://www.amazon.com/Female-Stereo-Splitter-Adapter-Extender/dp/B07C3M2GXH
You'll also need a set of RCA cords as well but typically people have a set laying around. Run your RCAs from the controller to the adapter and plug the splitter into the adapter. Lastly would be aux cords from the splitter to each speaker. Hope that makes sense. It's not professional but it will work and will probably be less expensive than any other solution