Headphones Not Working - DDJ 200

Hi,

I have a DDJ 200 and have connected it up to my smartphone via bluetooth using Edjing.

Therefore, the splitter cable is connected to my phone using the 3.5mm jack. From the speaker part of the splitter, I have a 3.5mm to 3.5mm going into the speaker and the sound plays through that. However, when I connect my headphones up to the speaker part of the splitter, I  get no sound through them at all.

I know the headphones work because I tried them out before connecting the speaker.

Is there any reason for this? Am I doing something wrong?

Thanks