Sound issues with my surround sound system?

so i just got a rca 1000 watt surround sound system. it works great with 1 huge exception. when the sound goes down to zero (such as a lull in a conversation or a break in action) a popping noise comes up. it is very distinct and i know it cannot possibly be intentional. i've secured every single wire twice to ensure proper connections. i've changed the source from my tv to a direct line from my bluray player and it does the same thing. am i doing something wrong or is something broken?