WIndows 7 - Use 2 audio devices simultaneously

I cannot figure out how to enable 2 audio devices at the same time on WIndows 7.  Specifically, if you right click on the volume button and go to "Playback devices", there will be 3 devices there: Speakers, Headphones, and HD Audio Device.  The "Speakers" are an 1/8" stereo jack in the back, the "Headphones" are a different 1/8" jack, and the "HD Audio Device" is the SPDIF coaxial audio on the back.  You can right click on these devices and "Set as default Device".  This makes that one the primary audio device and makes it play the audio.  I would like to be able to play out of my SPDIF (to my surround sound) AND my speakers at the same time.  In XP, it did this by default.  I've read around and I'm not sure if it applies to my issue or not, but some people were suggesting trying to install the Realtek HD Audio Manager and using it instead of Windows 7 control panel to possibly enable both at the same time.  This solution was in reference to front and rear audio jacks though, not SPDIF and speakers, also, many people had driver issues after doing so.  I didn't want to attempt.

Thanks
Gareth