I have a brand New American Bass VFL-550 All specs are underrated like all American Bass Amps.
American Bass Amps are known to sometimes put out over twice the advertised power.
RMS Ratings
4 Ohms 100w X 2
2 Ohms 200w X 2
1 Ohms 320w X 2
4 Ohms Bridged 400w X 1
2 Ohms Bridged 640w X 1
1 Ohm Stable, hight pass, low pass, bass boost