Nommo Headphone Port

Hi! I want to use my Razer Nommo with a subwoofer that I own. I tried using the 'Headphone' jack output on my Nommo speakers, but it disables the Nommo's audio and only broadcasts to the subwoofer I connected. Is there a way to disable this feature so I can use the speaker and my subwoofer at the same time? Thanks!