Connect 2 speaker systems to one computer

In my current setup, I have a speaker system connected to my monitor via 3.5 mm cable and my computer connects to my monitor through HDMI. I send the sound to my monitor which sends it to my speakers so that I have less wires connected to my pc. I recently got a second set of speakers (also 3.5mm) from my dad who doesn't need them anymore. I have an open aux jack on my computer and I was wondering, is there anyway to set the speakers on the HDMI as my front and the other 2 that I would put in to the aux port as my rear? Is there some speaker management software I could use? I have tried to use the windows sound settings but I can only run them as 2 independent speakers, not 2 front 2 rear.
 
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