Mass Loaded Vinyl: Smart Sound-Deadening Solution for Cars

Performance, comfort and safety may be the categories most car buyers look for, but a whisper-quiet interior should also be high on anyone’s shopping list. It’s not by chance that luxury cars use several layers of soundproofing materials to drone out external noises. Road, tyre, wind and noise emanating from the engine, transmission and exhaust can be irritating or outright dangerous at higher decibels. That’s the reason why car makers are investing more time and effort in soundproofing the interior and spurring a separate automotive division (NVH) to keep things quiet. 

How Vehicle Soundproofing is Done 

To get the best results, vehicle soundproofing is done in stages. Sound deadening, or isolating areas and car parts that vibrate, and preventing resonance through the vehicle with increasing speeds, comes first. Here newer cars use butyl-based noise absorption sheets in areas prone to vibrating, such as the firewalls and floor. The aim is to drown sound at the source and prevent sound waves from spreading to surrounding car parts. While butyl mats are efficient for most uses, and also prevent heat and moisture, an additional layer deals is required to deal with remnant noise. This is what’s called damping. 

The process can be achieved by using an acoustic foam layer, or for higher volumes, a mass-loaded vinyl sound barrier. Acosutic layers can be optioned in various thicknesses, from 4 to 12mm, depending on requirements and available space, and consist of a twin-layer construction with an open-cell outer, and a closed-cell inner layer lined with adhesive. 

Another alternative is in areas with more space in mass-loaded vinyl, or MLV. This is a thin mass-loaded upper vinyl layer with a 10-12mm thick closed-cell structure. Its main purpose is to add weight to the butyl layer underneath and deal with remnant sound waves that have come through. the material is what’s found as the stock solution in sound deadening in luxury and performance cars. While both materials are effective, MLV  is easier to install and can also be removed at any time. 

Benefits of Mass Loaded Vinyl Sound Barrier

Mass loaded vinyl is used across the board as a sound deadener and damper in construction, the automotive industry, production and processing facilities, recording and music studios, various industrial environments and in HVAC systems. The high absorption efficiency lowers volume levels by half in most cases. For cars and vehicles, the material has a long list of benefits: 

• Effective soundproofing – being dense and heavy, mass-loaded vinyl is effective in blocking the transmission of sound waves, barring airborne (tyres, brakes, wind, traffic) and resonating structural noise (engines, transmission parts and exhaust systems) from the cabin. Effectiveness increases by opting for thicker layers. 
• Durability –  regardless of where is installed, MLV is durable, won’t decompose (unlike older bitumen-based soundproofing) and should last the lifetime of the vehicle. Proper installation also means it proves a superior underlay for carpet, being resistant to liquids and chemicals. 
• Thermal insulation – an overlooked feature is MLV’s thermal properties. The material can contain radiating heat from hot engine and transmission parts at the source, keeping temperatures inside cool and comfy. 
• Easy and quick installation – applying a vinyl sound barrier to a butyl rubber base is simple. The material comes pre-cut in standard sizes but is simple to cut and shape with basic tools. It additionally works well with adhesive for permanent applications. 
• Versatility – mass loaded vinyl soundproofing can be applied in varying vehicle parts, and different vehicle types, Leftover pieces are also good for household uses, such as soundproofing doors, or garages. 

Where It’s Used

Floor pans, front and rear firewalls, roofs, boots, wheel arches and under rear seats are areas where MLV is used most often. The material provides mass and density to a previously installed butyl or acoustic foam layer. The added weight acts as a sound blanket, blocking sound that gets through the base layer, and preventing vibrations and resonance in adjoining parts. 

MLV can be installed in newer cars to enhance sound deadening and older vehicles fitted with bitumen soundproofing. The material also works in car rebuilds, when adding performance mods to race cars, and in utes, vans and 4WDs to block out rattling, clunking and grinding sounds in off-roading and work applications. 

Installing Mass Loaded Vinyl 

Consider the vehicle areas that generate the most sound, and use soundproofing products in a layered approach. Combine butyl layers, foam cell decoupled and mass-loaded vinyl for the best soundproofing results. Effective soundproofing involves layers and pieces cut to the exact dimensions, applying adhesive where needed, and eliminating gaps and air pockets. Each material is easy to cut (with scissors or utility knives), and pliable to fit onto uneven surfaces and contours. With proper installation, choosing MLV in the right thickness and density, and matching with other soundproofing solutions, interiors are freed from excessive external noises and irritable sounds, letting drivers focus on the journey.