I'm not sure when it was enabled in the stable Steam client, but it looks like 5.1 sound is now enabled for Steam Home Streaming on Windows hosts and clients. I said last year that this was a big missing feature for the platform, so I'm glad they actually did it.
It wasn't a smooth process to get it working, though. Although everything looked like it was configured correctly, whenever I tried the streaming there was no sound. I eventually found this forum post which said that the old DirectX9 runtimes ("DirectX End-User Runtimes (June 2010)") are need on the … Read more →