Computer audio starts at low volume then increases to normal

[JoeS99]

I have a MSI Windows 7 laptop that I use to capture/edit video with the Hauppauge PVR-2.
When I play video with Windows Media Player or VLC, the volume starts low then gradually increases to normal in a few seconds. This is very annoying if I am trying to edit (it happens with VideoRedo also). I looked at Control Panel and I don't see any setting for this gradual volume increase. Any ideas?

[Baldrick]

With all AUDIO? Video, music, games???

[JoeS99]

It does it with music and video, haven't run any games. There's RealTek HD Audio Manager and THX TruStudio Pro that I really haven't explored yet. If I open a video file with WMP, the audio starts at a low volume and increases in a few seconds to the desired level. If I pause, then play, the volume stays at the normal level. If I STOP and Play Again from the start, the volume starts low and increases to normal.

It's got to be some feature or setting in the audio driver, I just haven't found it yet.
I'll see if I can get some info on the MSI website later.

[jagabo]

Turn off the auto volume option (aka, night mode, loudness equalization, normalizer, etc.) in your audio settings.

[JoeS99]

Turn off the auto volume option (aka, night mode, loudness equalization, normalizer, etc.) in your audio settings.

Those options are already turned off.

[jagabo]

Then look for some other filter in the audio playback chain that's doing that. Probably the audio decoder. Use a player like MPCHC that lets you see what filters are in use. Disable all its internal audio decoders (close and restart the player for changes to take effect) then play a video. Right click anywhere in the player window and hover over Filters. You'll see a list of filters that are in use. Selecting a filter will let you change settings of that filter.

[JoeS99]

MPCHC shows these filters when playing an mp3 file:

Filters currently loaded:
- Default DirectSound Device
- LAV Audio Decoder (internal)
- LAV Splitter Source (internal)

I poked around looking at the settings and I'm really not sure what I'm looking for.

[jagabo]

Click on LAV Audio Decoder. Make sure Apply DRC... is off.

Note that will only have an effect on MPCHC since it's an internal decoder. To check the system installed DirectShow decoder disable MPCHC's internal decoder (View -> Options -> Internal Filters -> Transform Filters -> uncheck whatever audio type you're playing (AC3?)) then close MPCHC and start playing the video again. Check whatever filter is now doing the decoding and look for normalizing options.

[JoeS99]

Checking the audio filters got me nowhere and I put the problem aside for a while. I got to poking around a few days ago and took a good look at THX TruStudio Pro sitting in the System Tray. There's a setting called Smart Volume. Disabling it solved the problem. I've only been using the on-board speakers. I'll have to connect the COAX connection someday and try it out.