Sound Damping vs Dampening vs Deadening in Vehicles

What is Damping? How is it Different from Dampening?

What is Damping? How is it Different from Dampening?

Are you someone who likes to drive with the volume on your stereo turned up, but would rather hear the music instead of your car? Are you restoring an old vehicle and are concerned about driving at highway speeds in a box of metal? If so, one of the things you're going to want to consider is soundproofing your car.

However, when doing your research, you’ll find that there are numerous methods available. The first key step is to stop the metal panels from vibrating and rattling. If you’ve been researching how to do this, you’ve likely come across what looks like several different terms. Some people talk about deadening, while others damping or dampening. What’s the difference between these methods?

Are you someone who likes to drive with the volume on your stereo turned up, but would rather hear the music instead of your car? Are you restoring an old vehicle and are concerned about driving at highway speeds in a box of metal? If so, one of the things you're going to want to consider is soundproofing your car.

However, when doing your research, you’ll find that there are numerous methods available. The first key step is to stop the metal panels from vibrating and rattling. If you’ve been researching how to do this, you’ve likely come across what looks like several different terms. Some people talk about deadening, while others damping or dampening. What’s the difference between these methods?

What is Damping? Understanding the Science

We know that some of you like to get into the nitty gritty and understand the details, so we're going to take it a step further and talk a little science here. If that's not your cup of tea, feel free to skip ahead to the next section.

How Damping Products Work

When sound travels through sheet metal, it first changes from vibration in the air into vibrations of the metal. Then the metal reradiates this sound back into the air on the other side. As the metal vibrates, it flexes and returns to neutral at a very rapid pace. A good mental comparison is to think of a metal ruler that you can easily bend and then release to allow it to oscillate like a diving board while you hold it. Or maybe a large, bare piece of sheet metal that can be fluttered to create a sound like thunder.

A sound deadening material damps these vibrations by acting as a shock absorber. As the metal flexes, the rubber resists being stretched or compressed. This resistive force takes energy out of the vibration. The less the sheet metal vibrates, the less vibration energy that can be transmitted to the air on the other side.

To visualize this, think again about the metal ruler that we were bending into an arch. If a deadening material is applied to the top side of the arch, it would stretch slightly. If applied to the bottom side, it would compress slightly. Now imagine the ruler is switching from arched upwards to arched downwards many times a second. Each little stretch of the material pulls out some of the energy. A good sound deadening material is more effective at pulling out that energy, reducing the vibrations and thus the noise.

These two spring systems were displaced by the same amount of force. The undamped, black spring moves harmonically. The damped, blue spring's oscillations decay over time.

Dampening vs Damping vs Deadening

The short answer is simple. Our industry uses the terms deadening, damping, and dampening interchangeably. We sometimes use different adjectives to describe the "damping" to try and make it extra confusing. You'll often see these terms combined with a descriptive like sound, noise, vibration, or constrained-layer. Vibration damping. Sound deadening. Noise dampening. Constrained-layer damping (or CLD). They are all talking about the same process: reducing the amplitude of vibrations to reduce the noise.

Now while we are describing the same process, each of these terms has some nuance to it. And we’re perfectionists here at Second Skin, so below, you’ll find an explanation of the three to help you better understand how they are similar and different.

SOUND DEADENING

“Deadening” is one component of car soundproofing. When a car is traveling, its various metal surfaces vibrate, creating noise. To “deaden” the noise, you place a layer of soft material over metal surfaces to damp the vibrations, reducing the sounds that the metal surfaces emit.

By applying a soft material, like a sound deadening mat, the vibration waves are dissipated, muffling noise in the process. Any time you see the term “deadening”, it means stopping metal from rattling and is usually someone discussing how to soundproof a car.

visualizing a sound wave

SOUND Damping

Well, what is damping then? “Damping” is the act of reducing energy stored in an oscillation. An oscillation just means that something is moving back and forth in a consistent pattern, like a pendulum. There are many types of oscillatory systems, but they all slow down over time without additional energy. We want to slow them down faster by adding materials into the system.

In a car, the oscillations we want to slow down faster are vibrations. By “damping” the vibrating metal, we reduce the size and duration of the vibrations, thus reducing the noise. Sound damping sounds a lot like deadening right? When soundproofing a car, they mean the same thing.

spraying a car down with a hose is not sound dampening

No, dampening doesn't mean to hose down your car

SOUND Dampening

Dampening is a term commonly used to describe soundproofing a vehicle. When researching soundproofing your ride, you'll run across phrases like "sound dampening," "noise dampening," or "car sound dampening material."

Some people get snooty and say that “dampening” is incorrect because It means to get a material wet or moist. Unfortunately, they're only considering one potential meaning of dampening, which can also mean to decrease or to lessen. When we're talking about sound, dampening means to reduce the wave’s amplitude, or the maximum extent of a vibration or oscillation. Sounds familiar to sound damping doesn't it? That's why you see people use them interchangeably. This dead horse has been successfully beaten. Let’s move on.

Final Thoughts

If you don't have much experience with car soundproofing, it can be challenging trying to figure out what people are even talking about.

We hope that we’ve helped you move a little bit closer to understanding some of the vibration damping lingo. There’s a wide world of “deadening”, “damping”, and “dampening” out there and we hope we made things a little clearer for you. If we’ve learned anything over the years, it’s that informed customers make smarter decisions. Feel free to call us and let us know how we can help.