Suggestions for noise reduction for my Sportsman 1000 4-stroke generator?!

bakaneko

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Nov 16, 2015
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Thanks for the tip guys. Yeah, I will work on the exhaust too. I showed my instructor today and we were talking normally right by it but that doesnt mean I cannot do more~! :)
 


Steve Best

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Sep 22, 2012
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Can you summarize what you have done so far and how effective each step has been?
As you may notice, I am a bullet point type of guy!
What are you studying?
 

JerboaJohn

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Jul 29, 2018
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how is it mounted, floor/ground use or mounted on something? the hard rubber feet can be swapped out for a spongy rubber to trap vibration from resonating down
 

CrazyDan

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Its mounted like a pannier rack on the left side of the rear wheel. You can clearly see it in the vid.
 

bakaneko

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Sorry, guys, I am getting sick. Felt like crap. The generator is mounted to the left side of the bike chain and seat stay tubes at three points and supported by the axle nut. The generator itself has rubber feet that I think does a good job with vibration noise. It fits snug into the mount and I secure it via two 450lb cam straps used for motorcycle transport.

I guess to explain the reason for this possibly fruitless quest is that this is a hybrid with plus and minuses from gas and electric. One of the minuses of gas is noise. An ebike is deadly silent and great cuz you can have conversations, do vlogs, and listen to earbud music (if allowed). I like to get this generator to an absurdly low noise level.

Here is what i've done so far; its not much. Hard to find free polysterene and materials.

* Lined inside of panels with felt = ~5dB reduction
* Quick check placed a 1/4" plywood board on free facing side = ~0dB reduction

This reduction is according to my video editing software and an approximation. 5dB is barely noticable to the human ear but I guess if you are really paying attention to it you will pick up the difference...

Quick idiot test. I put a plywood board infront of generator with felt on inside. With and without board. Notta

 

bakaneko

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Nov 16, 2015
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Can you summarize what you have done so far and how effective each step has been?
As you may notice, I am a bullet point type of guy!
What are you studying?
CNC machining. I showed it to my instructor last night and he was like haha this thing is definitely a Frankenstein. :LOL:
 
C

China Girl Steve

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<SOME SNIPPED>
* Lined inside of panels with felt = ~5dB reduction
* Quick check placed a 1/4" plywood board on free facing side = ~0dB reduction

This reduction is according to my video editing software and an approximation. 5dB is barely noticable to the human ear but I guess if you are really paying attention to it you will pick up the difference...

Quick idiot test. I put a plywood board infront of generator with felt on inside. With and without board. Notta
In the garage you have sound reflecting off floor, walls and ceiling. For the single sheet of plywood to be effective it would need to be 2x or even better 3x the size of the sound source and have no reflection back to your mic. I mentioned it as part of SAR testing on a generator placed 100' from a work site, with no reflection sources. Try it outside. Not really practical for your application anyway.

You will need to box it in. There is acoustic foam (egg crate like stuff) used for motor enclosures (gas turbine, diesel, etc). It is quite effective, but an industrial supply item:

Hey, hardware store!
What about acoustic tiles?

Or better yet, this sort if you cab get them:

I'd suggest moving outdoors for blocker testing to eliminate reflected noise and get a better test of the materials.


Good luck, and good health!
 
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