I have installed a set of Polk db6500 components (10-100 RMS) and Polk db650 rear speakers (6-60 RMS) that is being powered by a Pioneer Avic-D1 HU (22 RMS x 4). Is the strongest amp I can get to power my speakers 60 RMS x4, or can I go higher say 75 RMS x4 or 100 RMS x4? Also how does it work...