Thank you very much Sir jhnkvn for the very thorough explanation on my queries. By the way, I'm contemplating on getting the sonus ecstatic amplifier which has the same rms rating as the enigma class. If I may ask Sir, is the performance of this amplifier the same as the enigma? because I've read that this amplifier retails for 9,500K. I'm also planning to put a headrest monitor of my ride. Do I need to change the stock speaker on my rear doors too? Once again Sir jhnkvn, many thanks for taking time to answer all my noob questions. You are very helpful to us newbies.