I'll try to remember to measure mine tonight, but 33dB sounds about like what I was getting when I dialed in my speakers. I have it ceiling mounted though and so it doesn't bother me very much--the only time I hear it is in quiet (no music) scenes in dialogue-heavy films. And even then it's just a light fan noise.
Former 35mm and Digital Projectionist @ Regal Cinemas
Currently watching on: BenQ W1070, 82" 1.0 Gain Screen, Darbee Darblet HD 43%, PS3, with Yamaha Aventage RX-A1030, SVS PB-2000, a Def Tech CS-8040HD, 2 SM65 for L/R, and 2 SM55 for surrounds.