I hear people complain that the XBOX 360 is too loud while others say its barely noticable. Since loudness is very subjective I wanted to check the sound from my XBOX 360 with a digital sound level meter. You can get one of these meters from a variety of places like Radio Shack. A lot of others on this forum may have a SL meter and I encourage you to test your XBOX 360 and post your results here. I think this will help set the record straight as to how loud the XBOX 360 really is. 
Sound Meter placement - 1 inch away and in the middle of the rear vents (directly inbetween the power cable and av cable connection). Sound Meter set to range 70. Response - Fast and Weighting - A.
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XBOX 360 Position: Horizontal
XBOX 360 Born Date: 11-19-2005
Dashboard SL Reading: 61-62 dB
Playing Game SL Reading: 66-67 dB
(tested with PGR3)
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Sound Meter placement - 1 inch away and in the middle of the rear vents (directly inbetween the power cable and av cable connection). Sound Meter set to range 70. Response - Fast and Weighting - A.
_______________________________________________
XBOX 360 Position: Horizontal
XBOX 360 Born Date: 11-19-2005
Dashboard SL Reading: 61-62 dB
Playing Game SL Reading: 66-67 dB
(tested with PGR3)
_______________________________________________