So I have a Macbook from last year and recently bough a logitech x540 speaker system. it is 5.1 surround sound system, but has a feature where you can activate the back 2 rear speakers and receive the full surround sound by pushing a button on the remote control. there are 3 plugs that logitech gave me to plug into my sound card-- an orange, green and black one. i was instructed only to plug the green one into my line out jack on my macbook, since I dont have the jacks for the orange or black cable.

Now, first of all, do I need an external/USB sound card with the 3 jacks on it that can produce 5.1 surround sound? Is my sound card deficient?

in one of the front speakers, the left one, there seems to be this noise that is emitted when you listen to the music at even half the potential of the speakers. it sounds as if its working too hard and is being blown out somewhat, even though it comes and goes-- sometimes you dont hear it somestimes you do.

How do I solve this problem? is it related to the sound card issue? How does my current sound card of the macbook factor into all of this?

I am debating whether I should return my logitech speakers and get 2.1 speakers, or buy an external sound card for 5.1 sound if such a thing exists.

Thanks so much-- I am a huge music fan that just wants my music to be great.