Here's my setup:I have an old surround sound system that only has HDMI Out and Toslink In (optical audio). I have my PC hooked up to my TV via HDMI and my cable box hooked up to my Xbox. Right now I have the Xbox hooked up to the surround system via Toslink to get surround sound audio. I also have the TV hooked up to the surround system via Toslink because there's no other way to output audio from the TV to it (my TV doesn't have ARC). The stuff I watch from my TV are mostly from Websites like Free TV Project, so it's not possible to get those on the Xbox.
Connecting XBox one to receiver with no hdmi port
Like dlCHIEF58 says, connecting Your Xbox One to the reciver with a Optical cable (Tos-link) is the suggested way to go.. I did that with my Xbox One and the difference in sound was clearly noticeable and well Worth it.. But I did need to go into the display and sound settings and enable "Bitstream out" and bitstream format Dolby digital (on my Samsung reciver)for it to give surround sound... Most Surround sound systems will support Optical audio i belive..support.xbox.com/.../configure-audio-settings
Connecting Older Reveiver to HDTV & Xbox One
Connect the Xbox to the TV with HDMI. Connect the optical audio output of the TV to the receiver. Check the TV manual on how to activate and use the optical input. Check the receiver manual on how to assign the optical connection you used (optical 1 for example) to an input (video 2 for example). You will now get audio from all your sources to the receiver.