When I stream a movie from the Vista MCE to xbox 360, or watch it through Webguide, the volume level is much lower. This can create unfortunate situations where you switch back to TV or your computer makes a sound, and it is way too loud because you turn your volume up to hear the movie.
For audio encoding I am using AC3 Filter. I asked Doug Berret at Webguide about this and he suggested checking the settings in the AC3Filter.
I started by updating my version of AC3Filter on the Vista MCE.
Here are the instructions for using AC3Filter with Media Center
Instructions obtained from: http://thegreenbutton.com/forums/thread/219065.aspx
Download and Install AC3Filter
Download DSFMgr.exe (Direct Show Filter Manager - Google it)
In DSFMgr look up the CLSID for AC3Filter and copy it to the clipboard
Open Regedit and browse to:
HKLM\Software\Microsoft\Windows\Current Version\Media Center\Decoder
Paste the CLSID you copied into the PreferredMPEG2AudioDecoderCLSID property in the registry (double click the PreferredMPEG2... label name and there you can paste the CLSID)
Open up AC3Filter config from the start menu as an Administrator (right click it and start as Admin) go to the system tab and set the filter merit to 'Use AC3Filter' instead of prefer other decoder.
On the AC3Filter config utility, click the Main tab. Increase the Master slider under Gain. You may also want to enable DRC (Dynamic Range Compression) and increase it using the slider.
To understand what this does please read: http://ac3filter.net/guides/dynamic_range_compression
A big consideration here is not creating problems by increasing these levels too much. If you do you will get clipping and clicking during loud sounds. On the AC3Filter website you can read all about this and make your own judgement on how to best do this.
In the instructions linked above, the author describes having a movie going and having the AC3Filter tool up so that you can see the levels and adjust accordingly. To do this, open AC3Filter Config Utility, click the System tab, put a checkmark next to 'Show Tray Icon'. Now, if you are using media center, when you open media center, in the upper right click the middle icon
to display media center windowed. Start a movie. On the systray click the icon for AC3Filter. You can now see the input and output levels and adjust accordingly.
So far I have increased both levels to about +12db. This seems to have helped. Now when I run a movie using webguide on my xbox 360, the sound is about the same as when watching tv, without having to adjust the amplifier.
Also if you are installing AC3filter for the first time and use Webguide you may need to run the webguide configuration tool and tell webguide to use the AC3Filter.