I have 8 ceiling speakers in 4 different rooms in my house. Each room has already a volume switch for 2 speakers on the room. I bought a very cheap receiver and I don't know if I did it right, the receiver keep shutting off every 20 minutes. I think its because it doesn't have enough power. I'm willing to spend some money to get the right thing but I need to know what to buy...do I need an AMP and a Receiver? And if yes, which one will I need to power all these speakers with no problem for 6 to 8 hours???