Reply to Running sound output through PC speakers, and using headphone on Kontrol S4 as well

Hello.

At the moment I can easily run the sound from my Kontrol S4 through my computer speakers.
But then I can't use my headphones that are plugged into the S4.

So my question is how can I use both (for obvious reasons) my headphones and my computer speakers?

(I'm only going to be getting new speakers to run from the S4 later this month so would appreciate the help on my above question, thanks!)