Setting up the receiver to 5.1

[Himanshu Mehani]

I connect my laptop to Harman Kardon AVR 170 via HDMI cable. I have kept the 'playback devices' configuration in laptop to 5.1 instead of stereo (default). I do get 5.1 sound though, when 'auto select' is selected. (I tested it by playing sample 5.1 videos).
But when I play stereo sounds like music or movies with stereo audio, the surround speakers becomes silent.
I want the receiver to play surround speakers even on stereo sounds. I understand I won't get that true 5.1 experience. But it looks really odd when only front speakers are in work.
I read somewhere that I should be changing the receiver settings to 'ext stereo', but my receiver doesn't have this setting. I do have surround modes, but those are also limited to: auto select, virtual surround and stereo. None of these three play the stereo sounds through surround speakers.

Info: When I connect the laptop to receiver, it shows 'Multi-CH PCM' and 3/2/.1 48 khz.
My laptop is HP envy 15 with IDT sound card.

 

[americanaudiophile]

If you set the surround mode to Dolby instead of auto the receiver will go to Dolby Prologic surround when a stereo signal is detected rather than stereo. If you are playing music you might try a different mode like Dolby Music.

 

[Himanshu Mehani]

If you set the surround mode to Dolby instead of auto the receiver will go to Dolby Prologic surround when a stereo signal is detected rather than stereo. If you are playing music you might try a different mode like Dolby Music.

Yah even I thought that but strangely when the 'playback devices' configurations in the laptop is in 5.1 mode instead of stereo (default), many of the surround modes in receiver gets disabled (including Dolby), leaving me with only three options: Auto select, virtual surround and stereo.

However when I change the configurations in the laptop back to stereo, I get all surround modes in the receiver.