Game chat cut off over speakers

The question I have is why does in game chat get cut off over speakers the moment you plug your headset/mic into your controller.

First let me explain my setup. I have Tritton warheads (http://bit.ly/28ZSt0a) which I use by plugging it into the back of the console with an optic fiber cable (so basically it acts as speakers). It is not compatible with the xbox ones voice function. So what I do to get chat voices playing through my Warheads is just have voice stream through speakers, since the headset acts as speakers as they’re plugged into the back of the console. I can chat in parties with no problem. I use the standard xbox mic (The one you get with your console http://bit.ly/29csLUi) as my mic I hang it around my neck with the mic infront of my mouth. The problem I’m having is with in game chat. I can hear in game chat through my Tritton warheads as long as I don’t have the xbox mic plugged into my controller. The moment I plug the mic into my controller it cuts the chat off to my Warheads and only stream it through the Mic headset (the official Xbox one I got with my console).

Hope I explained it well enough. I just want to know if there is maybe a work around for this so that I can have in game chat stream through speakers eventhough the mic is plugged in.
Thanks