Using audio from aux and video from hdmi...

I have been having problems getting my macbook to output 5.1 surround sound to the receiver...I have troubleshot everything humanly possible and I am out of options.

With a simple aux cable from my headphone jack to the color hookups on the front of my receiver (HT-R590) I get dolby surround.

Is there any way to use the aux cable for audio and the hdmi for video even though they are separate channels? If not, is there another way to do essentially the same thing?
I get perfect video but only 2 channel audio from my adapter/hdmi setup to my receiver.

I appreciate any help!

Hi comma,

Does this happen on other devices you have connected without using this conversion cable?

No it doesn't.
But I have tried multiple conversion cables and hdmi cables...also, it always worked in the past.
Right now I have the video with hdmi and the audio through the color cables in the back with another cable...
Seems to be working

Hi comma,

Thank you.

However, I have a question about this. When the audio is hooked up to coaxial or aux with a red/white cable the volume is very low and I have to turn the system all the way up to hear it well...is there something I could do to fix this or no? thanks!