You’ve probably made up your mind about acoustically treating your room. Let’s saddle you up before you confuse two completely different subjects and go on with queries like “do acoustic panels soundproof or block sound out from a room?” or “do acoustic panels block noise?”
Simply put, No! Acoustic panels do not soundproof or block sound out of a room because they are not designed to do so. Acoustic panels work on the principle of sound absorption only to mitigate short length, mid and high-frequency sound waves. Acoustic panels are focused on enhancing the sonic experience inside a space rather than keeping sound in or out.
Let’s take a closer look at what soundproofing is and why acoustic panels aren’t a great help with it.
Sound Proofing VS Sound Absorption
To get a better idea, you need to understand how sound waves behave and how these techniques primarily control those behaviors.
Soundproofing, also called sound isolation, simply prevents soundwaves from traveling/bleeding out of space.
Sound energy is produced from vibrations and travels in the form of waves through a medium, e.g., air. It travels from the source and causes everything it comes into contact with, to vibrate with the same frequency, including air, walls, furniture, or other objects in the room.
And unlike light, sound waves can easily pass/travel through most objects. This is why you can hear traffic noise even after closing all windows and doors.
The only way to achieve sound isolation is with mass and construction to allow this mass to “eat up” all the sound. Soundproofing or sound blocking requires building additional walls that allow air gaps for proper entrapment of waves.
Soundproofing material is usually very dense and thick. It’s similar to a thick foam, mass-loaded vinyl, caulking, weather stripping, wall lining, or door seals.
On the other hand, sound absorption means changing/controlling/maintaining the sound inside a room for better sound quality.
Sound waves will travel from the source on a straight path until they hit a hard surface and bounce off to travel again. This creates millions of unwanted reflections that can mess up the sound quality in a room. This is where acoustic panels come to the rescue! They change the dynamics of how these waves move by using absorption.
If placed at the right spots, acoustic absorption works to reduce reverberations and echoes from high frequencies. They are mostly used to treat listening rooms, churches, restaurants, recording studios, and every place where critical listening is a priority.
Why Acoustic Panels Don’t Soundproof or Block Sound Out of a Room?
Soundproofing requires treating each and every part of a room because sound waves can leak out from even the smallest nook. To completely block the noise out of space, you need to take care of both the airborne and vibrational impact of sound.
It requires a perfect covering of blow points (almost all of the wall) with high density/mass products. With that, you need to use different materials and placements to cater to different sound frequencies. Less dense material such as thin foam can take care of a high or mid-high range of sound frequencies. Whereas low frequencies have longer wavelengths and need more closely packed, high-mass material to stay in or out of a room.
Moreover, rooms that are meant to deal with louder, powerful sound energies need to decouple because vibrations are too strong to be held by a wall-connected treatment (acoustic panels/foam or bass traps).
On the other hand, acoustic treatment only treats target areas/spots in a room for different sound issues. For instance, flutter echo, standing waves, and unwanted resonances from high frequencies can cause sound waves to scatter and clash throughout the room.
Acoustic panels are formulated with a layer of foam framed in wood at the sides and the back, and a fabric cover at the front. This construction lets them absorb high and mid sound frequencies and reduce noise caused by them. Low frequencies, however, pass beyond the porous foam and through the wall.
This is why acoustic panels cannot soundproof or block sound inside a room! The insulating material used in their formation is not enough to trap long wavelengths. Just like waves can escape through acoustically treated walls, sound waves can make their way inside as well.
Frequently Asked Questions
How thick should a wall be to block sound out?
A wall should be 5 to 6 inches thick in order to keep sound out of a room. The wall should be made at least a foot thick with sound blocking material for complete blockage for concrete walls.
Can you FULLY soundproof a room?
Yes! You can fully soundproof a room if you:
– Treat the ceiling with hanging or attached acoustic panels/foam.
– Place acoustic panels (standing or hanging) at critical reflection points in the room to absorb high frequencies.
– Place bass traps or acoustic corner wedges to absorb low frequencies that congregate in the corners of the room.
– Place window frames and door seals.
– Use soundproofing or noise-blocking paint on the walls.
– Leave air gaps/spaces in walls during construction of the house.
In other words, build a room within your room!
What materials can block sound?
You can block sound waves only by converting their kinetic (motion) energy into another form of energy (usually heat). A sound-blocking material should make sound waves lose energy through friction between its fibers/voids and the air particles. It should be thick, heavy, and impenetrable so sound waves cannot pass through them.
The best material to soundproof or block sound out of a room is mass-loaded vinyl or acoustic wedge foam. You can paint or install them under the carpet to reduce airborne noise.
What absorbs sound the best?
Technically, any porous, soft, and pliable material can absorb sound. Open-celled surfaces are best at absorbing or “sipping in” sound waves coming their way. Fabric or cloth-covered acoustic panels or foams, glass or mineral wool, synthetic fibers have a very high sound absorption coefficient. Such materials are great for absorbing sound.
Do acoustic panels block sound?
No, acoustic panels only prevent sound waves from bouncing around the room. They can only reduce noise inside a room by clarifying speech, limiting reverberations and echoes.
What is the cheapest way to soundproof a room?
The cheapest way to soundproof a room is probably doing it yourself. Using window treatments, heavy curtains or acoustic foams can absorb maximum sound from going out or coming in. Another rather expensive way to soundproof a room is to paint the walls with soundproof or noise-blocking paint.