LosIsATool 5,000+ posts
CarAudio.com Veteran
They don't make a M4b.. And from testing the 80.1 didn't do rated if I remeber correct.The amps are rock solid and do well over rated. From what i have seen the 20.1 shares a board with the m4b. Dimensions could confirm this as i didnt see them side by side. I run a 20.1 and love it. The flatlyne subs are beast *** sq subs. Want to try a dp 15-18 if anyones interested in trading for the sub in my sig.