How to Build a Soundproof Generator Box | Soundproof Cow

How to Build a Soundproof Generator Box

How to Build a Soundproof Generator Box
August 20, 2021

A reliable generator that can give you power in a pinch is great to have. But anyone with a generator knows how loud they are.

If you’re using a generator around the campfire, for an outdoor gig or at home while waiting for the electricity to kick back on, you’ll want to limit the noise it makes.

A DIY soundproof generator enclosure is a low-budget solution that’s easy to build and does the trick.


Here’s everything you’ll need to build a generator box:

  • Medium-density fiberboard (MDF)
  • Mass-loaded vinyl (MLV)
  • Acoustic foam
  • Ventilation duct
  • Green Glue
  • Acoustical Sound Sealant
  • Circular or table saw
  • Drill
  • Tape measure or ruler
  • Paper and pencil

Building Your DIY Soundproof Generator Enclosure

Generator enclosures are easy to build — just follow these steps.

Step 1 — Measure and Mark Your Materials

Generators come in all shapes and sizes, so measure your MDF to ensure yours will fit in its box. Be sure to double- or even triple-check your measurements.

Mark lines on your MDF with a pencil and record the measurements on paper in case you forget.

Step 2 — Cut the MDF to Size

Use your lines as a guide to cut your MDF to the perfect size with your circular or table saw.

Unless your box is a perfect square, you’ll need two pieces for the floor and ceiling, two for the long edges and two for the short edges.

Step 3 — Create Ventilation Holes

With your boards cut and ready to go, measure two holes large enough to fit the ventilation duct — one on the piece that will be the box’s lid and another on one of the sides.

The lid hole should be closer to the top piece’s edge than its center, but choose the edge furthest from the side ventilation hole.

Step 4 — Add Your MLV

Generator motors produce a lot of airborne noise, so install Mass-Loaded Vinyl sheets inside your box as a reflective layer.

Cut the MLV to cover the MDF’s interior surface and use Green Glue to stick it in place. Next, cut ventilation holes into the MLV.

Step 5 — Add Your Acoustic Foam

MLV addresses airborne noise, but now you need something to reduce impact noise — the sound your generator produces from vibrating on the ground.

Cut and install acoustic foam panels inside your box using Green Glue as your adhesive. Once again, cut ventilation holes.

Step 6 — Fasten Your Pieces Together

With six MDF/MLV Composite sheets ready to go, it’s time to screw them together. Only fasten your five base pieces — leave the lid detached or add hinges for extra credit.

Step 7 — Seal the Gaps

Your DIY soundproof generator enclosure is nearly ready to go, but there may be cracks along the edges where sound can pass through. As a finishing touch, add Acoustical Sound Sealant to fill in any cracks.

Step 8 — Install the Vent Duct

As your final step, run your vent duct through the two ventilation holes and make sure it fits as tightly as possible. Try to leave multiple bends so the soundwaves have a greater distance to travel.

Violá — your generator noise reduction solution is complete!

More Tips From the Soundproof Cow

Interested in picking up some more helpful soundproofing tips? We’ve got more to give! You can contact the Soundproof Cow to hear from our noise experts. Or, browse our soundproofing inventory for materials you can use at home.