[SOLVED] cannot control AC3 volume

I'm running Windows 8.1 Pro with "K-Lite_Codec_Pack_1090_Mega.exe" and "klcp_update_1091_20141222.exe" installed using default settings. I've noticed that on some movies I cannot control the volume using either the MPC-HD (x86 and x64) volume control nor the system volume control. After some experimenting I've determined that the movies which have this issue use Dolby AC3 audio.

For example, one movie with the issue is Harry Potter and the Sorcerer's Stone. When I view the properties in MPC-HD, it shows "Audio: Dolby AC3 48000Hz 6ch 256kbps [A: English [eng] (ac3, 48000 Hz, 5.1, 256 kb/s)]".

Any ideas on how to resolve this issue? I'm sure it has to do with whatever filter is handling the Dolby AC3 audio but I don't know how to change it.

Mez

That happens if you enable bitstreaming. When bitstreaming, the audio data is send to an external receiver. The receiver does the decoding, and is in control of the volume.

Codec Tweak Tool > Audio Output > disable audio pass-through

Thanks for the solution! I had chosen HDMI pass-through during install since the computer is connected to my TV via HDMI. Changing it to disabled resolved the issue.