Silencing the Roar: The Power of Mass-Loaded Vinyl Soundproofing in Your Vehicle

It’s a fact: when it comes to high-quality sound deadening, today’s automobile owners are more concerned about reducing cabin noise than ever. Even car buffs who relish the sound of high-performance machinery can appreciate the need to keep road, wind, and tyre noise to an absolute minimum.

There’s a reason the world’s most luxurious vehicles are synonymous with overriding quiet: their double-skinned cabins can contain as much as 150kg of sound-deadening material, cocooning occupants inside a virtually impenetrable vault of acoustic insulation. It’s proof that layered sound deadening can work in any vehicle when used properly, and you’ll be surprised by just how much of a difference a top-quality barrier material can make for your car or wagon, but without spending a fortune.

Mass Loaded Vinyl Gives Your Car Optimal Acoustic and Thermal Protection  


If you own a sports car, a custom, or a combi, and are still on the fence about whether installing aftermarket Stage 2 insulation like mass-loaded vinyl soundproofing barriers (MLVs) would make a difference in cabin noise, then it’s important to understand their exact role in the overall sound dampening picture. As their name suggests, MLVs use mass to block the propagation of sound waves and are engineered to be used in conjunction with Stage 1 sound dampeners. The more efficient the Stage 1 sound dampening on your vehicle is, the more effective an MLV will be; and depending on how your deadening layers are organized, an honest 10dB – 15dB reduction in interior noise is easily achievable.

Victoria’s Car Builders manufactures a high-density, mass-loaded vinyl sound barrier material from limp, barium-loaded PVC that’s perfectly suited to blocking out all kinds of road, exhaust, and other external noises. While Stage 1 deadeners like factory-installed bitumen padding and aftermarket butyl sheets are designed to eliminate the tinny resonances created by external panels, decoupled (independently floating) Stage 2 barriers are positioned directly above the deadener, and are specially made for areas such as:

  • Atop floorpans and transmission tunnels;
  • Inside wheelwells, footwells, and quarter panels;
  • Against firewalls and rear bulkheads;
  • Under seats and inside door cavities; and,
  • Inside rear panels in combis and vans.

Not surprisingly, with their grain-faced mediums and woven textile backings, mass-loaded vinyl barriers do more than just use their weight to block exterior sound. They’re also incredibly effective at blocking the transfer of heat from the road, engine bay, and exhaust systems. It’s a combination of qualities that makes them the only sound-deadening material that’s perfectly suited to provide both thermal and acoustic protection.

Decoupling Lets You Get the Most from Any Stage 2 Sound Barrier

With a robust thickness of 2mm and weighing 4kg/m², Car Builders’ mass-loaded vinyl barrier makes for a durable, fully removable under-carpet layer that’s both heat and moisture-resistant. What’s most crucial to remember about mass-loaded vinyl soundproofing, however, is that its effectiveness is linked directly to it being decoupled. MLVs aren’t good at blocking vibrational energy, and allowing a vinyl barrier to come into direct contact with a Stage 1 deadener significantly increases the likelihood of it transferring Stage 1 vibrations into the cabin. This is why a cell foam absorption layer is needed between the deadener and the MLV.

Car Builders’ 3mm and 6mm Insul-Layer is a versatile, closed-cell foam pad that can be used as a cushion to go between a Stage 1 deadener and a Stage 2 vinyl sound barrier. It’s the ideal choice when it comes to preventing unwanted noise transfer, and boasts a host of simple, but essential qualities that include:

  • Lightweight (0.4kg per sheet @ 3mm, and 0.6kg per sheet @ 6mm);
  • Straightforward peel and stick adhesion; and,
  • Resistance to deterioration from heat or moisture.

By varying the quantities and thicknesses of Insul-Layer foam used either above or below a mass-loaded vinyl noise barrier, you have the flexibility to tune the amount and even the frequency of the noise entering the cabin. You can even use a spray adhesive to glue multiple MLV layers together and further increase your reflective mass.

Easy Steps to Getting the Most From Your Vinyl Layer


Because vinyl noise reduction barriers rely entirely on their mass to reflect sound, they’re at their best when they’re used to cover as much continuous area as possible. Even small gaps between vinyl noise barrier sheets can have a big impact on their effectiveness though, which is why it’s worth taking a few simple steps to get the most benefit from what they have to offer.

  • Get a good cover. MLVs aren’t designed to be used as carpet-like surface layers and are prone to marking and discolouring when left uncovered. That’s why when not used with another Stage 2, or Insul-Layer type padding, a high-quality stretch, or moulded carpet is the best way to protect them.
  • Stay in position. Although soundproof vinyl barrier materials need to be decoupled to do their job, allowing one to move freely under a carpet can also be dangerous. Velcro or dual lock fasteners are both excellent ways to ensure the barrier stays stably situated while still remaining decoupled.
  • Close the gaps. The mass-loaded vinyl tape and specially formulated glue supplied with high-quality Mass Noise Liner Joining Kits are superbly matched to produce a total, no-overlap seal along the mating surfaces between MLV sheets.

The Final Word

At the end of the day, there’s no getting around the fact that when it comes to sound deadening, there’s an unavoidable weight tradeoff. Adding material to your car or truck is going to make it heavier, but by carefully choosing your barrier materials, you can keep the weight gain to a minimum while maximizing your acoustic insulation.

Mass-loaded vinyl soundproofing barriers can give you the silence you want, but without spending a fortune on sound deadener, or adding armfuls of petrol-guzzling weight. It’s one of the best investments you can make in your car or wagon, and it’s one that you won’t regret making.