Woody Grayshon: seems to be running happier with the modified exhaust,
Out Of Place Ninja: 15 decibels is nothing. Get it below around 50 and you would be doing good.
Dick Trickel: But you only took it down 15 decibels....A lot of work for little reward (IMHO) If it had dropped by 40%,then I'd be cheering.
itsabig: this works.....nothing like the mass of terra firma to absorb all of that clatter, and it's very easy to route air flow in and out!
itsabig: most of the solutions i've seen on youtube miss one basic of sound attenuation. if you put an enclosure around the sound-source, you're simply installing a speaker-cone effect to further radiate the sound you're trying to suppress. basic sound damping requires a void between the origin of the sound, and the outside environment.
allow an area between the enclosure and the outer shell, and you'll half the decibel level, or even more....double walled with few connections works, look into it!
silverbankruptcy: I agree with you, the sound comes mostly from the motor running. I built a sound enclosure for mine. Video at 3GE_qqRMWN8
Kurt Kolb: If you need a really quiet generator, I suggest a Honda Inverter model. I have an EU2000 and it is much, much more quiet than this thing in the video. But if you're stuck with something similar, I would try a Super Trapp muffler and the generator box first. I am of the thought that bad things can happen when exhaust is re-routed. And I think in the final scene in the video the noise level is actually more mechanical than it is exhaust.
William Elliott: Do you have any thoughts on building a separate box to run an exhaust outlet into? I live in a town home and I need to keep a generator really quiet. I'm going to make a generator box, but i was curious to see if you have ever attempted to run the exhaust into another sound deadening box or if you had any thoughts on it.
Kurt Kolb: Wouldn't that make starting, stopping, and refueling a bit difficult? What about rain and pooling water in the hole? I would think building an enclosure would be a better method.
Richard Cavalier: I am thinking just BURY it in a square hole witha plywood/fiberboard top? Of course routing the exhaust out and provide a fresh air pipe...Opinions welcome!
bigdogintexas: Agreed, I find that a much larger sound deading factor comes from using a fiberboard "enclousure" that fits around the generator, a lot of sound, and I mean a lot, actually is coming from the motor and not out of the exhaust system, though the exhaust is certainly a prime source as well. A fiberboard enclouser is portable to an extend that it can be broken down and folded, and put back into "shape" for use when generator is out of storage, or used away from a "fixed" location.
Kurt Kolb: In this particular application I don't feel the benefits gained were worth the cost. I believe I paid about $180 for this configuration and I would have returned it for a refund if the finish wouldn't have started burning off during the test. The generator isn't as loud as before and the percussive sound of the original muffler is gone, so there is some benefit. Then again, this was a $500 6000w generator. If I wanted quiet I would need two Honda EU3000 units which would be closer to $3k.
hooverrandy: I know the SuperTrapp mufflers are pricey but they "sound" worth it.