A cheap way to quiet a cheap genset (motorcycle muffler)

[BrotherNomad]

For those comfortable fashioning metal, or at least comfortable with bolting and fitting; here is a cheap (under $100) means to quiet a cheap genset. Some of us don't have money to buy a HONDA or YAMAHA generator, the gold standard in portable generators. This involves taking a motorcycle or small car muffler and fitting it to the exhaust of peace & quiet enemy #1. Some people in the comments have wrote they reduced their gensets noise by 50%!

Here is the how-to:
http://joelsgarage.blogspot.com/2006/03 ... ffler.html

[trilobyte]

Another way to dampen the noise of a generator is to build a baffle, which requires even less skill and can probably be done for less with wood and fabric. Check the boards or the internet at large, sound baffles are an easy way to reduce the noise you, your campmates, and your neighbors have to deal with. Bonus points for the baffle also serving as a bit of a dust barrier, too.

[Captain Goddammit]

This is doodoo.

I've done the car, motorcycle and even barrel-of-water exhaust treatments on those loud lawnmower-engine generators. It doesn't work.
The article mentioned the problem: the exhaust isn't where all the noise is coming from! The whole engine radiates noise. Maybe you can quiet it a little, but it won't be "quiet".
Baffle boxes are your best bet for these things.

But if you think quiet generators are too expensive, let me explain a few things.
I have owned countless generators of all sizes from 1000 watts to 12,000 watts and everything in between. I'd have saved a lot money not wasting it on crappy ones, only to find out I never wanted to use them because they're too obnoxious. They also use too much fuel. It's not the cost of gas - remember, you have to BRING all that fuel.
You'll find out those same things.
But here's the killer: I paid $2000 for a pair of Honda EU2000s, over ten years ago. I just sold them for $1400! And I ordered a pair of brand new ones again for $1800.
My old ones only cost me about $50 a year to own. And I could have just kept them, they were still in awesome working shape. I only sold and got fresh ones because I could so easily.

This is one of those times where the good stuff ends up costing you less. And you'll enjoy them instead of hating them.

[chuckularone]

That is the righteous truth there Capt'n

[maladroit]

You can find used or refurbished Champion inverter generators around the $400 mark.

It'll be 5% as loud as a crappy 2-cycle contractor's worksite / Harbor Freight / 1960's old open frame generator. No joke.

I doubt 50% reduction in noise is possible, but even if it was...that 3 decibel drop isn't enough. The inverter generators run about 50-60 dB, the crappy open frame, full-throttle-at-all times generators are 80-100 dB.

Taking the worst inverter and the best cheapster, that's a difference of 80-60 = 20dB. We're talking about SPL, so the way decibels work, the best cheap generator would actually be 10 times as loud (and accounting for human perception be 4 times as loud). The sound will still carry 10 times as far though. So maybe if you're really lucky and comparing against a not-so-great inverter generator, a measured 50% SPL reduction would still be several times louder than an inverter.

If you put psychological effects into the mix, there seems to be an audible yet ignorable level of background noise, which cheap generators consistently breach. They'll become a focus of attention, and even if twice, thrice, or four times as loud...will be 100 times as annoying.

[Elliot]

As much as I am generally in favor of D-I-Y projects, I must join the chorus. Cheapo engines make a horrible mechanical racket, separate from exhaust noise.

Everything is a matter of priorities. Paying for a Honda EU-series (or equivalent) is no different. A Burner may have to skimp on something else to afford it, but a generator is the wrong thing to skimp on.

[mdmf007]

You can make loud generators quiet and its not done with the exhaust - all good generators have good enclosures. Point in fact. I bring a 2.5MW gas turbine to playa yearly, it powers quite a bit of the infrastructure you all love. Without the enclosure this GE turbine will deafen you at 100 feet - permanently. In its enclosure, you can talk next to it and listen to the steady hum of 3400HP at 16000RPM.

A honda EU2000 is loud as hell if you take the enclosure off. Running in its enclosure you can carry it like a lunch box and talk to people around you and they may not notice its running. So build a sound enclosure, direct the sound upwards four sides four feet high is plenty for the teeny generators. Insulate the inside with the aluminum sided foam panels from a box store, and go from there. Test it at home. Remember that air circulation may be necessary to keep it from overheating.

[maladroit]

I bring a 2.5MW gas turbine to playa yearly, it powers quite a bit of the infrastructure you all love. Without the enclosure this GE turbine will deafen you at 100 feet - permanently. In its enclosure, you can talk next to it and listen to the steady hum of 3400HP at 16000RPM.

Jesus. I would love it if you were running that beast, enough to fly an attack helicopter, and the only load was a single string of Christmas lights draped over a tent.