Audio Systems: Factory specs, rms power, factory radio

Question
I have a 1999 Mazda B3000 SE 4x4, It is 100% OE I want to know what the RMS power and FM sensitivity is for my origional radio. It is a CD AM/FM Cassette.
Looking to replace it with a Dual XD2MA400. will upgrade speakers later to match head unit.

Answer
There is no way that the Dual XD2MA400 is going to give you better sound or FM quality
it can be louder but with a lot of distorsion find a better brand radio
your factory radio its only 20w rms per channel, this are real power not dual 40 50 watts