Silencing loud things (part 2)
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- Опубликовано: 19 окт 2023
- Hi guys, this is part 2 of this series about soundproofing my noisy shop vac.
In this part, I´m comparing different sound absorption materials (inbetween layers of drywall) against each other, greenglue, mass loaded vinyl and ordinary butyl sealant. I have to admit that I didn´t intend to do this comparison originally, but on the way I got more and more curious on what material has the most punch. Well, I found it out. 
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Glad to see there is a part three. Certainly a very inexpensive way to soundproof a noisy shop vac. My obvious question - one I'm sure will be answered in the following video - is about heat. We all want the quiet life, but not if our trusty shop vac ends up melting in the process. Oh, thank you so much for sharing.
This vac has 2k watts, so a lot of energy. On average, I have the vac running for 5-10 minutes, rarely longer than 15 minutes. The exhaust air is warm, but not hot. It seems to me that it is designed to be cooled by the air that is going through the vac, less the surface of the bin. But I would recommend to alway be around when it is running. And I have a smoke detector on the ceiling above the shop vac.
This is a great video. Thanks for doing the research. I'm sure this will save many people a whole lot of money.
Thanks for taking the time to produce part 2. Very interesting results, MLV looks to be the way to go for sure on your project. I built an enclosure for my camvac following the general principles from your part 1 video. It’s just an mdf box with some fibre board underlay attached to the inside walls. It works really well. The loudest part now is the noise from the air being pulled through my machines rather than the camvac! Look forward to part 3 👍
Yeah, the outgoing air carries a lot of noise. I think I found a practical way to reduce that. Wait for part 3, I worked parallel on it, won’t take too long
Thank you for this data. I start my vacuum box today.
Can't wait for the final results once the build is completed, good luck.
Hello Tim Could you try and find a way to quieten the Db levels of a mitre saw? Besides the motor noize the Blade is like a Cymbal from a Drumkit and rings out every time you Raise the Blade after cutting the Wood.
Hey Michael, unfortunately I don´t own a miter saw and never used a miter saw. Im afraid, at the moment I don´t have a helpfull answer.
I am somewhat of a layman, so this question may seem a bit obvious, but is it possible that using less butyl sealant could increase sound dampening further due to less points of contact allowing the transmission of vibration? For instance, I know the bottom panel probably needs the support of the two rings you installed, but the sides could possibly be held at a distance with only a few points of contact in the corners. I'm drawing on my understanding of heat transfer here, so I imagine the science isn't exactly the same, but if you want to isolate the inner box from the outer box as much as possible I think reducing total sealant usage is a viable option.
Yeah, good question. On the other hand, The air between both layers is a factor too. With just one ring there might be more resonance than with a second ring damping the vibration. It’s everything but trivial
Seems like reaching perfection would be incredibly time consuming. The effort vs efficiency graph would be almost asymptotic. It probably wouldn't be worth it considering you've basically achieved a near analogous result to the more expensive options, but hypothetically it might be best to focus on avoiding patterns that increase the resonance at the frequencies that spike on your data sheet.
Q: "is it possible that using less butyl sealant could increase sound dsmping?"
A: NO. Butyl rubber's purpose is to attenuate the vibration, and more contact is better. Butyl rubber is used to quiet large metal surfaces (as found in luxury cars), and the most effective technique is to use "constrained layer damping", which is a sheet of Butyl rubber sandwiched between two metal sheets. Very effective!
That makes sense. Thanks for the clarification.