At 36 decibels, the Benq SU917 has a quite loud noise level compared to most of the other multimedia projectors that have been on the market for around the same time as this projector. The average noise level of multimedia projectors of this spec and age is 32dB, and the noise levels range from 21dB to 45dB.
Other 36dB noise level multimedia projectors currently available that you might want to look at include the Epson EH-TW6600 (£1,303) which has better reviews.
If you don't mind having a louder noise level then you might want to look at the VPL-CX236 (£1,102.42) (34dB and cheaper), or the VPL-CX235 (£1,104.01) (35dB and cheaper) both from Sony.
What does "noise level" mean?