
A soundproof generator box will significantly dampen your generator noises allowing for a quiet and peaceful environment.
In addition, a soundproof box for a generator can be used to dampen noises produced by a noisy air compressor in your garage.
As you can see, this multipurpose box is important for different reasons.
In this guide, we’ve detailed a step by step guide on how you can build a soundproof generator box at home for your generator and any other generator sized appliance at home to quiet your generator.
How to Build a Soundproof Generator Box
In order to build a soundproof generator enclosure, there are materials needed. Let’s have a look at these materials:
- Medium Density Fiberboards (MDF): This is the main material that you will use to make the generator box.
- Foam Mats: Will act as a soundproofing layer in your noise-proof generator box
- Mass Loaded Vinyl: it’ll serve as the first soundproofing layers in your generator box
- Ventilation ducts: they help supply airflow for the soundproof generator box
- Green Glue: you’ll use it to glue edges down. It’s also effective in noise dampening
Other tools you’ll need for this project include screwdriver, hammer, right-angled ruler, measuring tape, a saw (circular or table saw) paper and pen.
DIY Building a Soundproof Generator Box
Before proceeding, it’s important to note that you won’t completely soundproof the generator because the vents will leak some noises.
The vents are important as they help prevent overheating by providing regular air supply in and out of the generator box.
Step 1- Take Measurements
Generators are available in different sizes and so do all soundproof generator boxes.
The first important step is to take the measurements of your generator before you can make the enclosure.
Make sure to pay attention when taking the measurements as a simple mistake might ruin your entire project.
I would recommend taking the measurement once or twice before you begin cutting.
Jot down all the measurement in a piece of paper. Add a few inches to the sides to allow for enough space for ventilation and insulation.
After you’ve taken all the measurements and added a few inches to the sides- jot down the final measurement. Now it’s time to get our hands dirty.

Step 2: Cuts the sides of the box
Now that you have all the measurements ready grab the medium density fiberboard and cut out the sides of the generator box.
If you can’t get your hands on an MDF, you can use regular plywood.
However, it’s important to note that medium density fiberboard has better soundproofing properties than regular plywood.
Use a pen and a right-angled rule and make the generator box measurements on the MDF. Double-check the markings and then cut.
Use a table or circular saw to cut out the board. It’s important to make sure that you cut according to the measurement you previously made.
Step 3: Make Vent Holes
Measure the diameter of the ventilation duct previously purchased for this project.
Mark out two circles on the plywood or the fiberboard.
- The first vent should be located at the ceiling of your box. Make sure to place the circle closer to the side than in the middle of the board.
- The other ventilation should be on the sideboard
After you’ve marked everything as specified above, lay down the boards on a table and place the “ceiling” board in the middle with the “side” board around it.
Step 4: Install MLV insulation
Layers are very important when it comes to soundproofing. Layers of free space, sound gaps, and layers of materials are effective for soundproofing.
An effective soundproofing material is mass loaded vinyl insulation. It’s the first layer to use when building a soundproof generator box.
Measure the sizes of the boards’ pieces you cut out and then cut MLV to exact sizes as those boards. Then glue the MLV directly to the insides of the boards.
The edges of the MLV can be tough to glue them properly, so it’s important to watch out for those. Use green glue to take care of this problem for you.
Step 5: Glue the Foam Mats
Foam mats are great in reducing generator noises in your soundproof generator box. Add a layer of foam mats to the ceiling and walls of your soundproof box.
You’ll need to take the measurements of the foam mats in regard to the respective board sizes and then cut them accordingly.
You’ll need to glue the mats down on top of the MLV and also glue the edges using the Green Glue.
Step 6: Mount the Box
Assemble all the walls of the generator box around the ceiling and then screw them or nail them into place.
Alternatively, you can install hinges to allow easier access to your generator.
Step 7: Vent Ducts Installation
The last and final step would be to install the ventilation ducts into the holes created in step 3 above.
Make sure to tighten the ducts into place; you don’t want them jumping around when the generator is operating.
Once you’ve installed the vent duct, your sound-insulated generator box is ready for use.
However if you find building a soundproof box for generator is too much work for you, you can invest in a quiet inverter.
Final thoughts on Soundproof Generator Box
A DIY soundproof box for generator is a lot cheaper than investing in a new generator.
Getting your hands dirty at times is a fun activity and in the end, will help you reduce vibrations and unwanted noises from your generator.
You can also read this guide on how to soundproof a generator (link here)