Multiple Audio Sources

I have two audio sources on the main camera, one for sound the other for music. I created a settings window with NGUI and attached sliders. Here is the code for that:

void Start () {
UISlider slider = GetComponent<UISlider>();
EventDelegate.Add(slider.onChange, masterVol);
EventDelegate.Add(slider.onChange, soundVol);
EventDelegate.Add(slider.onChange, musicVol);
}

// Update is called once per frame
void Update () {

}
void masterVol()
{
    GameObject.Find("MainCamera").audio.volume = +UISlider.current.value;
    GameObject.Find("MainCamera").audio.volume = +UISlider.current.value;
    //Debug.Log("Sound volume: " + UISlider.current.value);
}
void soundVol()
{
    GameObject.Find("MainCamera").audio.volume = +UISlider.current.value;
}
void musicVol()
{
    GameObject.Find("MainCamera").audio.volume = +UISlider.current.value;
}

As you can see it finds the MainCamera and the adjusts the audio volume, however it will adjust the first one it comes to and not the second. Is there a way I can differentiate the two audio sources?

I would recommend just putting each source on an empty GameObject that are children of the MainCamera