This is where I have a mixer interface between the Beatbuddy and speakers. You don’t need an expensive mixer. The Beatbuddy goes into the Line Inputs of the mixer. And the speakers are connected to the Outs of the mixer. The mixer then allows further control of the speaker volume (and EQ) if needed). I also have my acoustic guitar running through a separate input of the mixer. I am using 1/4" jacks for all connections.
Mackie Thump line may be an option…?