It'd work, but really unless the player offers some form of matrix processing (even just a simple steering logic similar to what the 980H and 983H from OPPO Digital provide for their 7.1 analog outputs) you are going to hit a compromise somewhere. Without that, when you run into those TrueHD, multichannel PCM, and DTS-HD MA tracks that are only 5.1 you are going to get just 5.1 via multichannel analog or settle for lossy DD/DTS 5.1 that you can expand to 7.1. Messy, isn't it?...