I only have critically listened to the 1.6 and the MG12. Both have good enough bass extension for me. But most would opt to get a sub for sub 40hz passages and slam for HT. The other higher models have a good enough extension that doesnt warrant a sub....at least for 2 channel stereo listening. The only way to tell, is a nice long listen at them. I personally know the planer diaphram is one big chunk of stretched mylar sheet or a true aluminum ribbon. That has a lot of area space to easily move LOTS of air. The MG20 is rated to go down to 25Hz so it does play the lower frequencies...but how good...that I'm not sure about.

Saturn