I can't clearly hear voices in some video files

[phayz]

I have a fresh install of Xfce 13.1.2 and have installed only official packages - i.e. I have not added any repositories to the default configuration of slapt-get/GSlapt. When I ran the installer I chose the "Full" option.

I am playing a video - Galaxy Quest to be precise - and find that I can't hear the voices yet all other sound effects are clearly audible. Even stranger is the fact that I can hear more clearly the voice of one of the alien creatures which has quite a deep voice. The voices of all people in the video are just audible but not loud enough to hear without headphones. I have tried changing the audio settings in the Xfce mixer and it simply hasn't helped.

In trying to work out what the problem might be I installed VLC and playing the same video file works as expected - i.e. all sound, including voices of all characters, are clearly audible. I tried playing the same file with Whaawmp! and again the voices are almost impossible to hear. Parole Media Player and Whaawmp! are both using GStreamer so I'm guessing the problem is somewhere there.

Does anyone know what might be wrong?

[mimosa]

Sounds like a codecs problem. Vlc rules when it comes to playing recalcitrant files, and has a trick or two more up its sleeve than the competition. Its volume control also goes up to 200%, which beats Spinal Tap's mere eleven.

[thenktor]

I remember having such a problem with Totem (gstreamer) and Apple cinema trailers. Probably the 5.1 downmix does not work well ant the center channel with the voices is not loud enough. My solution was switching to VLC and SMPlayer

beats Spinal Tap's mere eleven.

But eleven is more than ten!

[gapan]

It's either that the 5.1 downmix doesn't work well and the center channel is not loud enough as thenktor pointed out, or that you soundcard has different outputs for center, front and rear speakers and you're only using the front (or rear) output. You should be able to solve both issues with creating an ~/.asoundrc file.

http://alsa.opensrc.org/.asoundrc

[thenktor]

It's either that the 5.1 downmix doesn't work well and the center channel is not loud enough as thenktor pointed out, or that you soundcard has different outputs for center, front and rear speakers and you're only using the front (or rear) output.

AFAIk the downmix is done by the player software, have a look at your settings there.

[phayz]

Thanks to everyone for their replies. I'm amazed at getting so many replies, so quickly, to a bizarre problem. I have never had this happen before. I didn't mention at first that I had this problem with one other video file but I believe it came from the same source. I have other video files from other sources and in other formats that don't have this problem, so I knew it wasn't a hardware issue.

I hadn't thought of 5.1 downmixing, in fact I had never heard of this before. I am complete noob when it comes to audio and video, whether under Linux or any other OS.

I am happy that I have alternative video players with VLC and SMPlayer etc. My only problem with using VLC is that it bloats a GTK-only installation by quite a lot since it requires Qt. Oh well, as long as I can enjoy the humour of Galaxy Quest I'm happy.