Why MacBook soundcard fails?

[Jerr]

I´ve noticed that some files, sound as if I had an fx (reverb or long hall) over the sound. I can barely hear voices. I´ve been searching on the "sound preferences" but the only I notice is that when panning to either 100% left or rigth, sound comes to be better.

Does anyone knows why is this?

 

[TBi]

You might have the program you are using set up to output 5.1 sound and therefore it is trying to use the "center" channel for voice. However you don't have a center channel so it won't work unless you have a 5.1 system hooked up.

This is just a guess. I'm assuming your using windows for these reverbs. Check that your sound preferences are set to output stereo and not anything else.