The EP400 has more output than the 350. In Axiom's listening room, the EP400 was still overpowering at its 1/4 setting on the volume dial vs the EP350 sounding good at 1/2. Since the two were on the same channel, the voltage out of the receiver was the same. That room was 12'x20'x8' (1,920 cf)
My experience in my home was different than yours. The little EP400 couldn't give me any shake or feel while watching movies and the EP350 easily did the job. I have always thought of the EP400 as a music only sub or one for very small rooms.
