Why does your skullcandy lowrider sgs headset make a buzzing noise when in 360 chat?

Xbox 360 Chat? Have you tried different headphones to see if it's the xbox? Have you tried plugging your headphones into a computer to see if the headphones are the issue?

Skullcandy is a terrible headphone manufacturer. Chances are the headphones are faulty in some way; you can probably return them for a new pair.