FINALLY! Someone that understands noise propagation.. I came from TV where we used big generators in production and this is the basic design for 300KW generators that are almost totally silent. Good job!
I like your approach to sound deadening. I worked for Radio Shack back in 1980's where we had a sound room for demonstrating audio systems. The walls were covered with sound absorbing foam panels and suspended ceiling material. The wall panels had grooves cut into the segments so that the wall surface was in a 1 inch by 1 inch grid. This would break up the sound wave patterns for dispersal and limited reflection. One other factor , I noticed in large office buildings......that the air handling /cooling units were mounted on SPRINGS on the floor or suspended from the building structure. That is like Technics turntables which have spring loaded feet so sound is minimized from affecting the base and vibrating into the tonearm. The platter is rather heavy/ dense to absorb sound. Many generators have rubber feet, some like rubber coated springs. Just food for thought for those who still want to experiment. Nothing ventured.....nothing gained
This is the best video on this subject I’ve seen yet. I’ve been thinking of something similar but I just don’t have the knowledge about the subjects, your explanation was excellent thank you
Definitely best video on quiet box for Generator. I'm gonna use this similar design and material for my box. For lower frequencies and vibrations maybe some sound dampening material they use on cars can be placed on the metal internal walls.
Wow! Good job. In order to create a sound proof wall in a house, I've used metal drywall spacers to float the drywall from the studs. The noise gets transferred through contact of the mass. If you greatly reduce the contact you greatly reduce the noise. Also I hear that noise has a hard time going around corners which is why your design worked well I believe. I'm going to build a sound box with a slanted roof because of the snow and include a door for easy access to the generator panel. Thanks for a well done video and all the ideas
Great design! The only way to mitigate bass frequencies is to reduce sound vibration through materials. Basically build two walls with an air gap between to stop vibration. What may work is to use two 1/2” polyiso boards with acoustic sealant in between. Also use acoustic sealant between materials and joints. A lot of low bass is probably coming from the bottom where the generator is seated. Some sort of isolation pads or the sandwich board mentioned above would help with that. Research music studio isolation walls and you’ll get the overall concept of low frequency mitigation. I’m an architect by trade. You’re on the right track! I like the cold and hot side concept and baffling with your design.
I helped design sound enclosures for high-speed mechanical dot matrix systems. Service access is essential. Heat is very important too. Don’t stop improving the thought process. Weather looks to be overlooked. Keep up the good start young man! Printers were from Printronix in Irvine Calif. 👍🏻
I have trawled through the videos and got SOOO frustrated with the "DIY" approach, which never seemed effective. Congratualtions on having an UNDERSTANDING of sound levels/frequencies and how to attenuate them effectively. Your approach is educated, critically thought out and analytical. CONGRATULATIONS AND THANKS!!
Hi Jerome, I'm glad you found my video helpful. Here are the materials I used for my build. 45in steel utility box, Princess Auto Hot Buy (these are not normally stocked) www.princessauto.com/en/45-in-steel-utility-box/product/PA0008821407 Toggle latches www.princessauto.com/en/large-toggle-latch-assembly/product/PA0008664377 Roxul Comfortboard www.lowes.ca/product/foam-board-insulation/rockwool-comfortboard-80-insulated-sheathing-118325 Blueskin www.homedepot.ca/product/bakor-blueskin-weather-barrier-9-inch/1000403476 Misc items from your local hardware store: 1/2" Drywall 1/2" plywood PL premium construction adhesive
Nice video bro! nice design approach. I'd like to follow your design but with bigger dimension for the sake of better airflow, did you measure the temp inside the box on both compartments? Thanks for sharing the video
Hi Erik, thanks for checking out the video. I have been able to do some comparative testing at cool ambient temperatures (55). The videos for that should be out soon! In short, the engine case air temperature rise under load in the hush box vs under load out of the box isn’t much different. I’m still waiting for a hotter day to see if there is a greater temp rise with higher ambient temps.
Hey, i just noticed you use a 0.7 kW propane inverter group, is it significantly quieter than gas ? I’m planning to use a gas 2.6kW, i probably won’t get the same results 🤔
I don't believe the fuel type has any noticeable effect on the operating sound of the engine. Your gas powered unit should perform just as well as a propane generator. People convert gasoline generators to run on propane all the time... The determining factor for noise reduction is going to be the construction of your generator and encasement. If you can start with something that is already quiet your hush box will work that much better... There is a wide selection of gas inverter generators so you should be able to find a quiet one. Also note, if you are going to enclose a gasoline powered generator you will need to consider 1.spills and 2.ventilating gasoline vapours from the box. Venting is continuous when the generator is running but when it is off, no air-flow through the box accumulate explosive vapours.
Hi, I did do some temperature & noise testing in a follow up video. In summary the engine ran fine with no concerning temperature increase. An interesting observation is the engine (in or out of the hush box) gets hotter after it is shut down as there is no more air being moved by the engine fan. The takeaway is to leave the hush box open for 20-30 mins after stopping the engine.
I always laugh when someone builds a "quiet" box and pipes the exhaust straight out and sometimes even against a brick wall..lol. Ive leave my generator in the shed with most of the other power equipment. I have a crank open window and a gable vent. plug the gable vent in and open the window and you can be on the street and not know who has the generator running....... except that the damn lights are on... hahah. We can go 9+ hours on a tank and when it needs filling, well opening up the shed just lets fresh air in
Use tempature laser gun to check temp at max watts out the box and in the box. If over load light comes on or stops making power this is a warning on these inverter generators. If still overloaded and over load light keeps comeing on generator. inverter board will burn up they are no safteys on these inverter generators. I burned one up the inverter board died engine run but no power!!!
you really achieved quite a reduction with you combination of hard (drywall) and soft (rockwool) ....and controlling the path of sound waves. That little unit was quite noisy before and then effectively silenced , all the other youtube videos had marginal results with just basic boxes but still leaving big vents...dyna mat from the auto industry is a good idea as well
You are correct about the harder and softer materials. Eventually I would like to build a new box that introduces an even denser material to control the lowest frequency components.
Generators have a built in fan that draws cool air in from one end, and exhausts it out the other to cool the engine. I am using the engine fan, just extending the path that cool air takes coming in and extending the path the hot air takes to leave.
No time now that summer is in full swing! Been camping for the past three weeks and we are already getting ready to leave for another 4 weeks pretty soon. Maybe I’ll get a short out shortly…
Hey m8 ! your design is neat :) I'd like to know your opinion : what do you think, 2 layers of drywall on each side of the box to mute low frequencies ? My goal is 50 dB, maybe i'm too optimistic there :D
If it is going to be a stationary box? if so you could use some acoustically heavier materials like cement board for tile. Or make a smaller box within a larger one, then fill the space between the two with a dense material like sand or concrete. If weight is a concern you could build a 3/4" plywood box and layer in the drywall. 50dB is getting down in the roots of the grass but which weighting are you targeting? A or C? C-weighting measures sound pressure level (SPL) over a wider section of the audio spectrum, this means that it will account for the lower-frequency components being 'heard'. The low frequency noise will be the hardest to mitigate. A-weighting on the other hand essentially 'ignores' the low frequency content and only measures a narrower section of the spectrum. THIS is how generator manufacturers can make ultra-low SPL claims. They measure the SPL from 23' away and use the dBa scale. If they used dBc the numbers wouldn't look so nice. But as we know, ignoring something doesn't make it go away. The box I built has shown measurements near 52dBa, and near 56dBc.
@@rad1876 Hi rob, i appreciate your response, it's super detailed :). I want to equip my truck to sell ice cream :D and yes, weight is a concern. Also, i think you have a point, plywood is lighter and absorbs better than a metal box, i'm also gonna try sand. I'll get back to you when i get desired results :) Thank you !
The exhaust is tempered with the engine cooling air. Same way the plastic housing on the generator doesn’t melt. The hush box is lined with rockwool which can withstand temperatures over 2100 degrees Fahrenheit.
there is absolutely no ventilation.... sure the generator is quiet when inside the box, but basically it is a very loud generator... I would have just spent the extra money and bought a Honda....
Your statement suggests you haven’t watched the video in it’s entirety or don’t understand how air flows through an enclosed generator. The same volume of air is moving through the generator case and engine shroud in or out of the box. The principle of the video is for demonstration and can be applied to your Honda unit to silence it.
Авто/Мото
FINALLY! Someone that understands noise propagation..
I came from TV where we used big generators in production and this is the basic design for 300KW generators that are almost totally silent. Good job!
I like your approach to sound deadening. I worked for Radio Shack back in 1980's where we had a sound room for demonstrating audio systems. The walls were covered with sound absorbing foam panels and suspended ceiling material. The wall panels had grooves cut into the segments so that the wall surface was in a 1 inch by 1 inch grid. This would break up the sound wave patterns for dispersal and limited reflection. One other factor , I noticed in large office buildings......that the air handling /cooling units were mounted on SPRINGS on the floor or suspended from the building structure. That is like Technics turntables which have spring loaded feet so sound is minimized from affecting the base and vibrating into the tonearm. The platter is rather heavy/ dense to absorb sound. Many generators have rubber feet, some like rubber coated springs. Just food for thought for those who still want to experiment. Nothing ventured.....nothing gained
I think this man is a perfectionist!
I like the idea of different layers of sound reading.
This is the best video on this subject I’ve seen yet. I’ve been thinking of something similar but I just don’t have the knowledge about the subjects, your explanation was excellent thank you
Thanks, glad you found the video helpful!
It's amazing the amount of noise reduction you're getting with this box. Great job.
Thanks!
Definitely best video on quiet box for Generator. I'm gonna use this similar design and material for my box. For lower frequencies and vibrations maybe some sound dampening material they use on cars can be placed on the metal internal walls.
Wow! Good job. In order to create a sound proof wall in a house, I've used metal drywall spacers to float the drywall from the studs. The noise gets transferred through contact of the mass. If you greatly reduce the contact you greatly reduce the noise. Also I hear that noise has a hard time going around corners which is why your design worked well I believe.
I'm going to build a sound box with a slanted roof because of the snow and include a door for easy access to the generator panel.
Thanks for a well done video and all the ideas
Best home made I’ve seen so far!
Cheers!
Great design! The only way to mitigate bass frequencies is to reduce sound vibration through materials. Basically build two walls with an air gap between to stop vibration. What may work is to use two 1/2” polyiso boards with acoustic sealant in between. Also use acoustic sealant between materials and joints. A lot of low bass is probably coming from the bottom where the generator is seated. Some sort of isolation pads or the sandwich board mentioned above would help with that. Research music studio isolation walls and you’ll get the overall concept of low frequency mitigation. I’m an architect by trade. You’re on the right track! I like the cold and hot side concept and baffling with your design.
Great video! But does anyone else feel kind of sad and nostalgic seeing equipment from Radio Shack?
In its day the Shack had everything!
Wow! Significant noise reduction, very impressive.
I helped design sound enclosures for high-speed mechanical dot matrix systems. Service access is essential. Heat is very important too. Don’t stop improving the thought process. Weather looks to be overlooked. Keep up the good start young man! Printers were from Printronix in Irvine Calif. 👍🏻
Great video vary good idea its almost like a quiet muffler on a car/truck concept
Fabulous job. If that brought down the decibels by up to 15 I can only imagine what it can do to a generator that’s much quieter.
✌🏽
I have trawled through the videos and got SOOO frustrated with the "DIY" approach, which never seemed effective. Congratualtions on having an UNDERSTANDING of sound levels/frequencies and how to attenuate them effectively. Your approach is educated, critically thought out and analytical. CONGRATULATIONS AND THANKS!!
Thanks, Glad you liked the Video!
One of the most effective results 👏👏
Wow that's awesome please build me one
Can provide a materials list? What size Powerfist box do you have? Great Video! I've watched many and this one is at the top.
Hi Jerome, I'm glad you found my video helpful. Here are the materials I used for my build.
45in steel utility box, Princess Auto Hot Buy (these are not normally stocked)
www.princessauto.com/en/45-in-steel-utility-box/product/PA0008821407
Toggle latches www.princessauto.com/en/large-toggle-latch-assembly/product/PA0008664377
Roxul Comfortboard www.lowes.ca/product/foam-board-insulation/rockwool-comfortboard-80-insulated-sheathing-118325
Blueskin www.homedepot.ca/product/bakor-blueskin-weather-barrier-9-inch/1000403476
Misc items from your local hardware store:
1/2" Drywall
1/2" plywood
PL premium construction adhesive
Nice video bro! nice design approach. I'd like to follow your design but with bigger dimension for the sake of better airflow, did you measure the temp inside the box on both compartments?
Thanks for sharing the video
Hi Erik, thanks for checking out the video. I have been able to do some comparative testing at cool ambient temperatures (55). The videos for that should be out soon!
In short, the engine case air temperature rise under load in the hush box vs under load out of the box isn’t much different. I’m still waiting for a hotter day to see if there is a greater temp rise with higher ambient temps.
Hey, i just noticed you use a 0.7 kW propane inverter group, is it significantly quieter than gas ? I’m planning to use a gas 2.6kW, i probably won’t get the same results 🤔
I don't believe the fuel type has any noticeable effect on the operating sound of the engine. Your gas powered unit should perform just as well as a propane generator. People convert gasoline generators to run on propane all the time...
The determining factor for noise reduction is going to be the construction of your generator and encasement. If you can start with something that is already quiet your hush box will work that much better... There is a wide selection of gas inverter generators so you should be able to find a quiet one.
Also note, if you are going to enclose a gasoline powered generator you will need to consider 1.spills and 2.ventilating gasoline vapours from the box. Venting is continuous when the generator is running but when it is off, no air-flow through the box accumulate explosive vapours.
Great job, the only question i have still unanswered (yet): Did you conduct the temp measurements and if so what was the outcome ?
Hi, I did do some temperature & noise testing in a follow up video. In summary the engine ran fine with no concerning temperature increase.
An interesting observation is the engine (in or out of the hush box) gets hotter after it is shut down as there is no more air being moved by the engine fan. The takeaway is to leave the hush box open for 20-30 mins after stopping the engine.
@@rad1876 Installing a cooling fan above the airflow opening could that help, that cools the cooling area could that help?
How did the temperature testing turn out? I'm concerned about the heat to the motor and generator.
I recently posted a couple testing videos, check them out for results!
I was very impressed. Where did you buy the box you used?
It was on special at Princess Auto about a year ago.
Lower frequencies are non directional & push more air
Is a Fermacell floor panels a good housing? Along with rockwool on the inside..
Any kind of dense panel board should work. Concrete board would be another option.
@@rad1876 thanks for the answer how about a ventilation too give a extra cooling at the front?
I always laugh when someone builds a "quiet" box and pipes the exhaust straight out and sometimes even against a brick wall..lol. Ive leave my generator in the shed with most of the other power equipment. I have a crank open window and a gable vent. plug the gable vent in and open the window and you can be on the street and not know who has the generator running....... except that the damn lights are on... hahah. We can go 9+ hours on a tank and when it needs filling, well opening up the shed just lets fresh air in
Okay 👍
what about air flow?
Air flow turns out to be great and now issues whatsoever. Check out my companion videos where I test the efficacity of the hush box.
Use tempature laser gun to check temp at max watts out the box and in the box. If over load light comes on or stops making power this is a warning on these inverter generators. If still overloaded and over load light keeps comeing on generator. inverter board will burn up they are no safteys on these inverter generators. I burned one up the inverter board died engine run but no power!!!
you really achieved quite a reduction with you combination of hard (drywall) and soft (rockwool) ....and controlling the path of sound waves. That little unit was quite noisy before and then effectively silenced , all the other youtube videos had marginal results with just basic boxes but still leaving big vents...dyna mat from the auto industry is a good idea as well
You are correct about the harder and softer materials. Eventually I would like to build a new box that introduces an even denser material to control the lowest frequency components.
@@rad1876 I just bought at big 12kw Westinghouse gen, will be building a little outhouse for it using your ideas
Love it How much cost?
$100 for the crate. Probably another $150-200 for the other materials so $300ish.
But I don't understand how you get getting rid of heat?
Generators have a built in fan that draws cool air in from one end, and exhausts it out the other to cool the engine.
I am using the engine fan, just extending the path that cool air takes coming in and extending the path the hot air takes to leave.
For as small as generator is it's pretty loud.
It's all relative. In this video I'm not measuring from +20' away like the manufacturers do.
Say no to crack, lol
Long time no vids how are u now
No time now that summer is in full swing! Been camping for the past three weeks and we are already getting ready to leave for another 4 weeks pretty soon. Maybe I’ll get a short out shortly…
Hey m8 ! your design is neat :) I'd like to know your opinion : what do you think, 2 layers of drywall on each side of the box to mute low frequencies ? My goal is 50 dB, maybe i'm too optimistic there :D
If it is going to be a stationary box? if so you could use some acoustically heavier materials like cement board for tile. Or make a smaller box within a larger one, then fill the space between the two with a dense material like sand or concrete. If weight is a concern you could build a 3/4" plywood box and layer in the drywall.
50dB is getting down in the roots of the grass but which weighting are you targeting? A or C?
C-weighting measures sound pressure level (SPL) over a wider section of the audio spectrum, this means that it will account for the lower-frequency components being 'heard'. The low frequency noise will be the hardest to mitigate.
A-weighting on the other hand essentially 'ignores' the low frequency content and only measures a narrower section of the spectrum. THIS is how generator manufacturers can make ultra-low SPL claims. They measure the SPL from 23' away and use the dBa scale. If they used dBc the numbers wouldn't look so nice. But as we know, ignoring something doesn't make it go away.
The box I built has shown measurements near 52dBa, and near 56dBc.
@@rad1876 Hi rob, i appreciate your response, it's super detailed :). I want to equip my truck to sell ice cream :D and yes, weight is a concern. Also, i think you have a point, plywood is lighter and absorbs better than a metal box, i'm also gonna try sand. I'll get back to you when i get desired results :) Thank you !
how doesnt it burn?
The exhaust is tempered with the engine cooling air. Same way the plastic housing on the generator doesn’t melt.
The hush box is lined with rockwool which can withstand temperatures over 2100 degrees Fahrenheit.
Thank you! Super helpful!
Nice design but unwise to use wood
Hasn’t been an issue yet!
gg
there is absolutely no ventilation.... sure the generator is quiet when inside the box, but basically it is a very loud generator... I would have just spent the extra money and bought a Honda....
Your statement suggests you haven’t watched the video in it’s entirety or don’t understand how air flows through an enclosed generator.
The same volume of air is moving through the generator case and engine shroud in or out of the box.
The principle of the video is for demonstration and can be applied to your Honda unit to silence it.
Way to much talking!!
😂
Seriously?