- Joined
- Apr 16, 2005
- Location
- Sharon, SC
@CasterTroy it kinds sorta is as simple as a percentage. dB is a logarithmic scale.
So for example a reduction of 10dB is a 50% reduction. An increase of 10dB is a doubling. etc.
However...that is only a small,albeit critical, part of the argument. The other thing that dramatically impacts noise level is surrounding surfaces. Generators are rated in a very specific ANSI test. It defines what distance and height and location the microphones are set up and what substrates are around it during the test. Since sound travels in waves and bounces off objects...lets say a generators is rated at 67dB at 23' (The ANSI standard is 7 meters which is 23 feet) and the surface is an exposed plywood floor and free air for the duration of 7'.
If you then place the gen on pavement and place a solid object, say a car or trailer, 5' to the left of the gen - go take the reading 23' to the right of the gen and the recorded level will be much greater than the published spec because sound is bouncing off the car or trailer.
Conversely put it on grass, or carpet and and it can be lower.
That is before we get into conversations about different fuel levels increasing or decreasing the weight and thereby the moment of inertia and increasing/decreasing vibratory noise and.... its just easier to say real quiet or kinda quiet.
And those are just the super highlights. Hell ambient temperature will change dB levels on an asphalt surface particularly.
So all it takes is a Youtube warrior to take a gen, develop the right circumstances be it by intelligent design or ignorant happenstance, a $20 radio shack dB meter, and next thing you know brand integrity suffers and a class action suit ensues.
So for example a reduction of 10dB is a 50% reduction. An increase of 10dB is a doubling. etc.
However...that is only a small,albeit critical, part of the argument. The other thing that dramatically impacts noise level is surrounding surfaces. Generators are rated in a very specific ANSI test. It defines what distance and height and location the microphones are set up and what substrates are around it during the test. Since sound travels in waves and bounces off objects...lets say a generators is rated at 67dB at 23' (The ANSI standard is 7 meters which is 23 feet) and the surface is an exposed plywood floor and free air for the duration of 7'.
If you then place the gen on pavement and place a solid object, say a car or trailer, 5' to the left of the gen - go take the reading 23' to the right of the gen and the recorded level will be much greater than the published spec because sound is bouncing off the car or trailer.
Conversely put it on grass, or carpet and and it can be lower.
That is before we get into conversations about different fuel levels increasing or decreasing the weight and thereby the moment of inertia and increasing/decreasing vibratory noise and.... its just easier to say real quiet or kinda quiet.
And those are just the super highlights. Hell ambient temperature will change dB levels on an asphalt surface particularly.
So all it takes is a Youtube warrior to take a gen, develop the right circumstances be it by intelligent design or ignorant happenstance, a $20 radio shack dB meter, and next thing you know brand integrity suffers and a class action suit ensues.
