DIY Soundproof Generator Box: How to Make One Yourself

People use generators to keep themselves supplied with power during outdoor trips when they spend nights in the wilderness. However, what all generator owners have in common is knowing just how loud and distracting those machines can get.

Creating a soundproof box around a generator can make a huge difference in terms of the noise without interfering with the generator’s function. These devices are so simple that you can make them on your own. They can muffle the noise from a generator so that it doesn’t bother you at all.

Those who want a premade solution can buy complete quiet generator boxes. However, if you are willing to make your own box, I advise you to give it a try. That way, you will be able to make the exact right box for your generator, with precise measurements and all the necessary features. On top of that, it is a straightforward process that doesn’t require any technical expertise.

This box simply needs to be placed around your generator to do its work. As long as your soundproof generator box has the appropriate venting ducts, you don’t need to think about it at all. Without further ado, here is my guide to making your own soundproof box.

What You’ll Need to Build a Soundproof Generator Box

Before getting into any work, it is necessary to be properly equipped in terms of both tools and materials.


Here are the tools that are needed to make the quiet box quickly and as described in this guide (but you can use any other adequate tools that can do the work):


You can use the following materials:

Soundproofing a generator with a quiet box.

Instructions for Building a Soundproof Generator Box

1. Measure the Generator

Generators come in different shapes and sizes. That’s why the first step to building a quiet box is to measure the generator. Make sure you don’t take this step lightly as you’ll end up with a box that won’t fit.

When you have taken your measurement, put them down on paper and don’t forget to add a few inches on all sides.

2. Build a Frame for the Box

Take the measurements of the generator and cut some furring strip boards to create a frame for the box. Start by making two sets of legs from the strip boards, which are a few inches taller than the generator.

Following that, cut a couple of small blocks from the furring strip boards. Then, screwed the small blocks onto the two adjacent sides of the central section of each of the legs. These small blocks are for the inside panels.

Afterward, screw together each separate pair of legs with a top plate, with the small blocks for the panels facing each other (and the generator). The purpose of the side panels is to hold the box together. Then, measured the distance between the leg frames.

3. Create the Panels for the Sides of the Box

Use a lightweight foam backer board to create the panels for 5 out of the 6 sides of the box (leaving the bottom side open). Namely, cut the inside and the outside panels according to the measurements you took from the frame.

Screw the outside panels onto the frame of the box.

Following that, use the small blocks to screw the inside panels onto them. The space between the outside and the inside panels should be equal in size to the width of the small blocks on the sides of the legs. As a result, you will get a double-paneled box with the bottom side open.

4. Stuff the Cavity With Insulation

Stuff the cavity between the inside and the outside panels with lightweight insulation. Following that, turn the box so that the open bottom side is facing up and cut your cheap insulation into sheets. Then stuff the cavity with sheets.

You can also use spray foam insulation if you know how to use it. Unlike traditional insulation, foam seals all the gaps, so it might be an even better choice.

Once that is done, cap off the bottom of the box with the furring strip boards. That way, the insulation will be safely sealed between the inside and the outside panels.

5. Cut Out a Channel

Use an oscillating multi-tool to cut out a channel for the exhaust pipe. That can also be done with a regular jigsaw.

6. Paint the Box

Once the box is constructed, paint it the color of your choice using a high-heat spray paint.

7. Install a Handle

When the paint dries, install a handle to make the box portable. Screwed a small block of the furring strip board on the inside of the top-side panel to serve as backing for the handle. Then, screw on the handle in that same spot, but from the outside.

8. Install an Extended Exhaust

Afterward, install an extended exhaust pipe on the generator. The channels you had previously cut out for the pipe and the cords to go through are now in use. The finished box is open on the bottom side, and you can use it by placing it over the generator. So, the channel should be wide enough for the long exhaust pipe to go through.

9. Finishing Touches

Before finishing up, cut out an opening at the location of the pull string. The purpose of that opening is to draw in cool air from the outside and to push the hot air away from the generator. That way, you will make sure the generator wouldn’t overheat inside the box because airflow is crucial for the functioning of the generator.

Finally, to further improve the level of acoustic insulation, add a small exterior piece on the inlet. That piece should be angled at 45 degrees and will serve to direct the sound downward in order to improve the noise reduction qualities of the box.

Watch this video tutorial:

Consider Upgrading Your Quiet Box

  • Using better sound insulation may produce better results. However, even regular and affordable store-bought insulation will make a difference.
  • You can add a fan to the box for the airflow, as well as outlet access.
  • As for the plugs, it is best to cut a square opening on the side with a latch that would accept the plugs.
Best Quiet Generators

Final Thoughts

You can make this soundproof box for any portable generator. People who often take their generators camping can easily bring the box with them or build one on the spot. It doesn’t weigh much since the materials used for the construction are lightweight.

The difference in noise levels you can achieve with this box is instantly noticeable. Just make sure you create proper airflow to avoid overheating and consider making further upgrades by adding a fan.

All things considered, I recommend making your own soundproof generator box because it’s a great way to save money and avoid buying a similar premade product.


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