Came from an Onkyo TX sr805 with Ultra THX certification and 135 real watts per Channel (this one has THX Select and 110). Speaker system is Atlantic Technology 4200 7.1. The 805 did have Dolby True HD and DTS Master Audio and sounded fantastic, but not HDMI passthrough for 3D, or Dolby Atmos. My concern that the 737 might not sound as good at higher volumes was unfounded. Absolutely excellent. Room size is 15 x 20 with 8.5 foot ceiling. Haven't tried Atmos yet