So I've done a lot of research over the last year n a half or so I've installed my own system lots of time I know most of the basics. I am looking to upgrade to new planet audio bb12ds they are 600w rms each. I was told by a professional installer that I would only need an amp that does a true 600rms to power BOTH of these properly...how true is this? Wouldn't I need 1200w rms to power both at full? Thanks in advanced, I'm assuning there are some pro installers here.