Since you can hear other audio fine but not the dialoge, few things we need to check on. Your post title is a bit misleading, you don't want to make your speakers louder you need to fix your audio channels.
1. Does this happen on all the movies you try? I have one DVD (The Color Of Money) that refuses to play right on my PC, the dialoge is way low compared to the rest of the audio.
2. Is this a DVD or a file?
3. Check your speaker settings make sure they are not set to 5.1, unless you actually have a surround system. You may be trying to output to a center channel (which is used for dialoge mostly) that you don't have. If you DO have a surround sound system, make sure you center speaker is plugged in properly.
VLC is a good media player, but may not fix the issue you are having as you get good audio just not with dialog.
Hello,I was watching a movie on my computer and I couldn't hear the voices but the music was loud and the volume was all the way up. Do you know how to make it louder so I can hear the voices?
i had a similar problem what i did was i when into my sound properties in the contol panel and messed about with it i was about to give up but there were enhancement options there so i turned them all on and it greatly increased my sound out put dont know if your laptop has these options ive got a hp g61 running windows 7 hope this helps
If you change your output to headphone instead of speakers you will get louder output because computers put out more power to headphones since they arent usually powered as speakers are. I used to do this to get an extra boost out of unpowered stereo speakers. Also it may not apply... you'll notice alot of cameras and other recording devices tend not to have the most favorable capabilities as far as small detail such as voice compared to jumbled background audio sharp contrast changes and rapid continuous movement..