assuming a gaming PC using windows, transporting video and audio via hdmi to a TV and connected an amplifier with a 2.1 setup to that. however the subwofer is controlled by the amplifier so all I want is plain stereo into the amplifier.

Now, when playing old games sometimes the audio is just off or very silent (like: wing commander 4, many gog games that use dolby stereo in the cutscenes) – this is because the software has “dolby stereo” hardcoded on the CD/DVD and windows assumes that the hdmi interface can process dolby stereo.

windows itself doesn’t help you here, blaming the game/the TV and it kinda annoys me to hear only the left and right channel and not the center, rear and subwofer channels – it apparently assumes that the game specifies the desired output or whatnot… and we all know who’s mother assumption is

remedy is an AC3 splitter or directshow filter
a very good one is included in the “shark007 codec pack” – get it here
I am sure there are others but that one is my favorite since I migrated away from CCCP (combined community codec pack) years ago (which was needed to decode mkv anime with dual audio, etc…)

just install the “advanced” package, use shark007’s recommended settings and then in the settings set up “2.0” stereo downmixing (or whatever you are feeding into your amplifier) – I have only two wires – left and right – for the moment. once I upgrade my amplifier this will basically work against me… but hey, first I need a better amp ;)