Hi, I just noticed recently that my sound coming through my 5.1 speaker setup sounded a bit lacking. So when I did a sound test on the speakers, I put my finger on each speaker to feel the vibration. As I was going through the test I didn't feel any vibration on the left speaker but I still heard the sound come from somewhere. I went into the balance settings on windows and turned it all the way to Left and that's when I heard the sound coming through the sub-woofer. Also when I change the balance to just Sub nothing is heard at all. What is the cause of this? Thank you for your time!