Hi, I'm a major DVD fan (550+) but when it comes to sound I'm not that well informed. I have a Dobly Pro Logic reciever with five speakers. I wanted to know if I can buy a Dolby Digital and DTS reciever and still use my speakers without having to buy new ones. Plus, on the back of my old speakers it says max input 30W. If I get a 600 watt reciever am I in danger of damaging my speakers? Any help would be appreicated.