I bought a new Pioneer DEH-P4800MP to replace my factory stereo in my 97 Camry. The factory stereo was a premium stereo with 6 speakers. I was expecting to just use my factory speakers for now with my new hu. I noticed in the HU install guide that they say the speakers should be 4-8 ohms and min. 50 watts. My rear deck speakers are marked 3 ohm/20 watts. Would I damage the stereo by connecting to these factory speakers? I don't really crank the volume up.