Generator quieting
A while back someone mentioned looking for a quieter muffler to reduce the noise of their gen. That question brought to mind that a video needs to be made which should clearly show that much of the...
Forum Discussion
SaltiDawg wrote:
What is the mechanism that you hypothesize for "internal vibration of the engine" to be seen as airborne noise?
TIA
Exhaust noise is "isolated" via the building.
When standing OUTSIDE you are hearing mainly the exhaust note with a slight bit of the gen vibration coming through the walls.
The building since it is wood and the floor is also wood does not 100% stop the mechanical noise but in that video the mechanical noise is reduced and it is good enough to show that the exhaust component is the smaller part of the overall sound level.
Concrete block building with concrete floor would most likely isolate the exhaust from mechanical better but I am not putting the effort or money into this demonstration to make a block building.
INSIDE THE BUILDING, the MECHANICAL noise IS what is LEFT OVER WITHOUT THE EXHAUST NOTE.
I connected flex pipe directly to the muffler outlet. The flex pipe makes a turn out the side of the building.
Moving parts inside the gen like valves, pushrods, piston movements, crank shaft and even slight balance issues resonate all through the engine case, the case then radiates the mechanical noise.
Smaller engines like in say a Honda Inverter gen have special attention paid to noise due to mechanical mass and vibrations caused by pushrods and valves. Part of that is a case design that may have reinforcements to specific areas that help to dampen the transmission of mechanical noise.
A pretty simple but yet effective 15 DB of noise reduction by placing the gen in some sort of box or in my case a out building.
Inside my home, I cannot even hear the drone of the gen.
