need help with audio problem

hi guys I'm very new to this forum just got my mac like a few months ago

my mac is OS X version 10.6.8
and the problem Im having is about the sound out put
I remember when I first had this mac when ever I'm playing a karaoke song on Youtube I can just move the balance of the speaker to the left via the setting of the sound out put I was able to turn off the original singer and still be able to hear the sound from both speakers from my ear phone

example clip คิดฮอด kid hod (karaoke)
http://www.youtube.com/watch?v=US0Fa7piddY

but after I downloaded a program called wire tab I can't do that anymore the sound would only come out from one side of my ear phone T.T

ps: ofcoz wire tab can fix the problem but I'm only using a trail version which will expire soon >.<

so if anyone can help me on how to fix this or recommend me another program to download would be much appreciated (free software plz coz I do not own any credit card or debit card T.T)

 

help plz T.T