Thank you for your effort you put down in research of Damping factor.
Have a simple explanation about so many amplifiers,my set up is a combination of hometheater and 2-channel for music,11 channels + 2 subwoofers with amplifiers including buttkickers with own amplification,2 channel with 2 bridged Inter-M 500 to upper registers and one 500 amplifier for left and right woofers with active crossover.Believe me this korean amplifier is a fantastic amplifier for very small money,but only the 500 model sounds good.So my expensive and powerhungry class-a amplifiers have to do service in surround channels,and for serious listening in two channel my Korea design "made in Kina" .