Hello!

I've got a problem with youtube/grooveshark/vimeo etc. sound when using my external 2.0 speakers. I can hear all the sound but the vocals. The melodic line goes on normally, but the sound the singer/actor makes is either hissing or there's no sound at all. The problem doesn't occure when listening to a song stored on my disc. Then, if I unplug my speakers and use the laptop's built-in ones, video sound goes on perfectly okay.
My speakers are JBL Duet.
It's more than sure it has something to do with the sound configuration but I cannot find out what the right setting is. I have also reinstalled the codecs (SigmaTel High Definition) and got K-Lite Codecs Pack.

Would be grateful to hear from you. I'm going crazy with this plugging and unplugging.

Iwa