Hi I posted before about this issue and have sorted it now. Here’s how I did it.
I think this will only work with this type of sounc card. If you’ve not got a 5.1 or above I think you need an external soundcard. Theres lots of posts about this elsewhere.
I’m running Windows 7 64 bit
Realtek HD 7.1 soundcard
2.1 speakers with subwoofer (1 output from machine)
Plug your speakers into the lime green output on your soundcard
Take your headphones out the yellow/gold output
Download ASIO4ALL (Google it, it’s the first result)
Open ASIO4ALL (little green icon on task tray when MIXXX is running)
Go to ASIO4ALL advanced (spanner icon)
Expand your chosen soundcard (I’ve only got one) and highlight all the inputs / outputs by clicking the power symbol on the left
Go to MIXXX options / preferences
Set Sound API to ASIO
Set Master to ASIO4ALL v2 channel 1-2
Set Headphones to ASIO4ALL v2 channel 3-4
Run 2 tracks hit the headphone button on one and hey presto your done!
Hope this helps.