Posted 29 October 2011 - 03:08 PM
Your system has been set up to output audio in a way your speaker setup does not support. The reason speech (which is typically carried across both left and right channels) is quiet or absent, is because in a surround sound setup, any audio that goes across both channels is output through a center speaker, which your system probably does not have.
This is rather simple. In Windows, you can set the audio type to be multiple-channel, such as 2.0, 2.1 (2 stereo with a sub), 3.0 (2 stereo, center) 3.1, etc.
What you want to do is go to your Control Panel.
From there, we're going to check two places.
One might be called "Realtek HD Audio" or something similar. (this is a very common setup)
In there, you can change, in the first tab, the sound profile you're using. If you only have your two front speakers, or if you have a speaker set which includes a subwoofer plugged into your two front speakers, choose "2.0" or "2 speakers". If you have a speaker set which includes a subwoofer plugged into a special plug in your computer case, choose "2.1" or something similar. Figure out, from those selections, which most closely matches the profile of what speakers you have in your setup. They should come with changing the pictures, to get an idea of what each means. Changing the profiles WILL NOT harm your computer, so it's safe to do, just make sure you get it right in the end if you want sound to be correct.
The other place is "Sounds and Audio Devices" (may be named something slightly different in Windows 7). In there, in the Volume Tab, next to Speaker Settings, click "Advanced". In there, choose the speaker setup that matches your configuration.
Hopefully this helps to return the audio to your system correctly.
If there are questions, please reply with what OS you have, and a listing of the items in your control panel that might relate to audio or sound, and I'll try to give more detailed instructions and screenshots if possible.