4.1 speaker setup (DirectX audio out)

[Anamon]

I have a 5.1 speaker setup configured as a 4.1 setup, since due to the location of my computer and my monitor setup, it is impossible for me to place the center speaker. For that reason, I want my applications to mix the center channel into the L and R channels.

This works fine for every Windows application except VLC player. In the Windows speaker settings, instead of using Quadrophonic (which would mean my LFE is not used), I choose 5.1 and in "optional speakers" deactivate the checkbox for the Center speaker. This has the effect that all my connected speakers—L, R, Ls, Rs, LFE—are used, while C is downmixed into L and R evenly. This, as I confirmed, works fine.

In VLC's settings for the DirectX audio output module, I do not have the option to deactivate the center speaker of a 5.1 setup, and Quad will again deactivate my LFE. However, the listbox also has a choice "Windows default", which I supposed should take my Windows configuration of 5.1 w/o center speaker. However, it always leads to the same effect as Quad (no sound from LFE).

In short: I think the speaker configuration option "Windows default" for the DirectX audio output plug-in is broken, and instead of its intended effect is equivalent to the "Quad" choice. Is there another way to get VLC to use a 4.1 setup, rather than a 4.0 or 5.1 one?

[Rémi Denis-Courmont]

If you keep the Windows default, VLC uses the configuration specified by the system, falling back to stereo if the configuration is unknown or monophonic. In no case will it fall back to quad. However, DirectSound does not define a 4.1 configuration, so VLC cannot detect possibly such a configuration.

[Anamon]

It is possible that the other applications I successfully tested were not using DirectX, and therefore were able to use the 4.1 configuration set up in Windows 7's audio panel.

Unfortunately the WaveOut plugin in VLC does not given any useful option either. Is there any other way to get VLC to use a 4.1 setup? I saw that MediaPlayer Classic, for example, has the option to map audio input channels to speaker output channels freely (although I didn't manage to get it to actually safe the settings). What I was wondering is if something similar can be done in VLC.


Edit: In the meantime I have found a solution, although I'm afraid it will not be helpful to everyone having the same issue. I have noticed that in the control panel of my Asus Xonar D2X audio interface driver, there are even more speaker settings. If I configure VLC to the 5.1 setting, and then in the Asus driver choose 6-channel for the input signal but Quadrophonic for the output signal, then the center channel is downmixed driver-side, without losing the LFE channel. So if no one knows about a good software workaround, I guess the answer is: get a good sound card.

[Rémi Denis-Courmont]

There is an audio filter for arbitrary channel remapping in VLC 2.1.0 and up (not yet officially released though).