I will test my XPA-2 and M80s in direct mode and see if I have any issues with heavy bass. The XPA-2's meters should help indicate when it is being driven too hard. I am also curious at what point the m80 woofers will start to bottom out. I don't see them producing really low frequency bass at very high levels without a sub to help. They do however produce a lot of punch with bass that is around 45-65 HZ (just guessing on frequency). With Rap music or any other low frequency bass I have to use my sub to get strong output.

M80,VP150,QS8,ERD-1,XPA-2,XPA-5,UMC-10,PS3,XBOX360,Dish VIP622,PB13 Ultra,Panasonic PT-AE3000U