Avoid Mistakes. Know What Sound Absorbing Foam Will Do… And What It Won't
Don’t buy a piece of foam, attach it somewhere in your car, and expect your car to be any quieter. Foam will not “block” unwanted noise like automotive mass loaded vinyl. It also will not work as a vibration damper for metal like our butyl rubber mat or liquid sound deadener.
Foam will, however, absorb airborne sound waves. The frequency and total amount of sound absorbed depends on the foam.
| Type | Product | Impact |
|---|---|---|
| Sound Deadening | Damplifier Pro, Spectrum Sound Deadening Spray | Stops noise from structural vibrations by deadening the metal |
| Sound Blocking | Luxury Liner Pro | Fused foam and MLV act as a heat and noise barrier |
| Sound Absorbing | OverKill Pro | Closed cell foam decouples hard surfaces |
| Sound Absorbing | Mega Zorbe | Open cell foam absorbs sound waves |
Foam Products Absorb Airborne Noise
Think of foam as a sponge, but instead of absorbing water it absorbs noise. Unlike a hard metal surface which will reflect sound waves, the porous foam surface allows sound waves to penetrate it. Once inside, the wave reverberates around the interior of the foam until it runs out of energy or it exits. Even when sound waves exit prior to dissipating, they will have less energy than when they entered. The thicker the foam, the better it will be at absorbing noise, especially low frequency sound waves.
For vehicles, we prefer to use thinner cuts of our acoustic foam because space is limited and the flexibility and ease of fitting makes it more practical.

What Makes a Good Sound Absorbing Foam?
If you’re looking to absorb sound, you’re looking for an open cell foam. Open cell foam excels at absorbing mid-to-high frequency sound waves. There are a ton of foam products out there, but most of them are not much use in your vehicle. We’ll get back to that, but to understand how foams are evaluated – you need to be able to read a chart.
This chart shows you how effective the product is at absorbing different types of sound.
- The y-axis ranges from 0 to 1 and shows the percentage of sound absorbed. 1 = 100% absorption
- The x-axis shows a range of hertz, indicating the sound wave’s frequency. In the soundproofing industry, an STC rating measures effectiveness from a standard range of 125 Hz to 4000 Hz – so many tests cover those frequencies.
- Each colored line represents a different thickness level at which the foam was tested. A thicker foam will absorb more sound.
Success on this chart means absorbing as much sound as possible, while keeping the foam as thin as possible. It’s an important measure of quality, but you need more than that to be good enough to put in a vehicle.

Sound Absorbing Foam in Vehicles: You Need 3 Things
For a foam to make the cut to go in a Second Skin vehicle, it needs to do three things:
Our foam products go through rigorous testing to ensure they can take a beating. These foam panels aren’t going on a soundproof wall to spend the rest of their lives 30 feet in the air. You’re installing them in a modern miracle of design and technology that is constantly exposed to heat, wind and rain, while traveling at sometimes lethal speeds on all sorts of terrain. This foam needs to be able to take a punch. But what foam do you need?
Open Cell versus Closed Cell Foam
If you're comparing open cell versus closed cell foam, open cell foam is a less sturdy product and will absorb water, so it needs a hydrophobic treatment to prepare the foam for vehicle use. Do not put foam that isn't water resistant in your vehicle, especially not the door panels! The trapped moisture creates the potential to grow black mold, which can literally kill you. Closed cell foam is denser and more rigid. It’s not very good at absorbing most sound waves, although it will do a little bit to stop low frequency sounds, such as engine and road noise.
| Product | Type of Foam | Touch & Feel | Sound Absorbed | Other Uses |
|---|---|---|---|---|
| Mega Zorbe | Open Cell Foam | Soft and flexible | Mid-to-high frequency noise | Class A fire rated thermal insulator |
| OverKill | Closed Cell Foam | Dense and rigid | Minimal; some low frequency noise | Decouples hard surfaces |
Mega Zorbe
Our Mega Zorbe product is a ½” thick melamine foam that we’ve treated to be more durable and hydrophobic. It’s great for thermal insulation, absorbs an impressive amount of noise, and comes with the option to include an adhesive backing for easy application.
Overkill
Our OverKill line of products come in 1/8” and 3/8” thicknesses and are excellent decouplers. OverKill’s primary uses are to squeeze it between plastic panels to stop rattles and to combine it with a mass loaded vinyl (like Luxury Liner) to create a noise barrier on top of your sound deadening materials. We have customers who swear they’ve shaved a couple decibels just by shoving OverKill behind cupholders.
A common use for both Mega Zorbe and OverKill is to install it inside the door panel as an easy way to improve the acoustics of the door. Mega Zorbe is more effective, as it’ll absorb a lot of the back waves, but OverKill will help a bit too – similar to how putting a carpet in an empty room helps a bit with acoustics.
Second Skin Can Help!
Each project is different. Let us apply our years of experience to help you find the right product for the job. We’re happy to talk through any project with anyone who calls in. We've seen thousands of jobs – let us save you some time. Second Skin is here to help!
Any vehicle that rattles or shakes, and most do, can benefit from sound deadening. Whether you installed a high-end sound system, are fixing up a hot rod, or just want to carve out a little bubble of comfort for your drive to work, Second Skin's sound deadening are best in class. Join Team Second Skin and turn any car into a luxury vehicle!