If you record music from home, have a large sound system set up, or just need to dampen sounds in a certain room, DIY soundproofing is one way to stop noise pollution without breaking the bank.
In this article, I’ll give an overview of some of the most effective and economically friendly materials for soundproofing your own home.
Table of Contents
- How Does Soundproofing Work?
- Soundproofing Materials and Methods
How Does Soundproofing Work?
Sound travels in waves, and the louder the sound, the larger those waves are. Soundwaves are like water and light in the way that they don’t require a specific shape to be heard. The waves will just fill the space until they reach our ears and vibrate, so we hear the sound.
To quieten sound, you need to shorten the sound waves, and the best way to do that is by using acoustic material. Acoustic materials will absorb some of the sounds and reduce the size of the waves, making them smaller by the time they reach our ears and therefore quieting the overall sound.
The best soundproofing materials are, therefore, materials that absorb the most sound and shorten the sound wave the most. This will stop sound leaking through walls etc, and into other rooms.
The effectiveness of a material in its soundproofing qualities is measured with an STC rating, which stands for Sound Transmission Class. The higher a material’s STC rating, the more effective it is at deadening sound waves.
Soundproofing Materials and Methods
Decoupling and Sound Clips
Decoupling involves ensuring that materials that are going to soak up a lot of sound waves are kept apart from other materials, therefore stopping vibration and the transmission of sound waves.
This is most effective at stopping low-frequency sound waves, as they tend to vibrate through things, while high-frequency waves will often bounce off surfaces. This is why bass and drum sounds from a party next door are more audible than higher-pitched sounds.
This is quite a major undertaking, as it normally involves adjusting the fitting of doors, walls, ceilings, and floors.
It can be made easier with the use of sound clips, which are small clips from which drywall can be hung instead of attached directly to the joist. They have rubber feet that deaden vibration and are much faster and easier to fit compared with decoupling the whole room, especially if the structure is already built.
Cavity Insulation – Foam and Fiber
Probably the most effective method of soundproofing involves the tried and tested materials of cavity insulation. Insulation of this variety can either come as wool-like matting in sheets or as a foam that is sprayed into the cavity and then expands to fill it completely.
This works so well as it deadens any sound waves traveling through the drywall and prevents further vibration. The absorbent qualities of the foam and/or fiberglass also work well to soak up sound waves and vastly reduce their wavelength.
Standard insulation works well for this purpose, but there are specialist soundproofing varieties out there, both in roll and spray foam form.
Mass Loaded Vinyl
Mass-loaded vinyl (MLV) is a dense yet flexible roll of high-density vinyl-based compounds which can easily be applied to many surfaces. Typically, MLV is composed mainly of barium sulfate due to its non-toxic and high-density qualities.
MLV works so well because it is entirely non-elastic, which means any sound waves that hit it are absorbed almost entirely, and vibration and transmission through the material are virtually impossible.
It is easily measured and cut to size and can be placed on walls, ceilings, and under carpets and flooring.
Green Glue is a brand of acoustic sealant that is favorable for use in soundproofing due to its minor elasticity and ability to transfer sound wave vibrations into the heat, which is highly effective at dampening sound leakage.
Apply it as a glue between layers of other soundproofing materials or as an alternative to caulking when filling cracks and gaps around windows etc. Its malleability means it will expand and contract with other building materials and won’t crack.
One of the main culprits for sound leakage when looking at how to better soundproof a room is always the cracks around doors and windows. Sound waves will find a way through these gaps, even if there is only a tiny crack, and plugging them is an ideal way to improve the overall sound-deadening qualities of your room.
Weatherstripping materials are applied around doors and windows and work by filling those air gaps with dense and sound-absorbing material. They are very cheap and easy to apply – a must when soundproofing!
Normally made for use with heavy or loud machinery, anti-vibration pads can be a great and cost-effective way of deadening sounds coming from amps, speakers, and subwoofers. They work by absorbing vibrations and therefore blocking soundwaves from traveling directly from the equipment and into the floor.
Coupled with floor underlay, they can drastically reduce noise leakage downwards.
Improving the acoustic absorbency of the floor is a vital step in soundproofing. A layer of dense and absorbent materials laid between the subfloor and the top layer of the floor can greatly reduce sound vibrations traveling downwards and vibrating through, or reflecting off, hard floors.
Specialist soundproofing underlay is available, but it tends to be on the more expensive side, and generally, anything thicker than 3mm works well to absorb and deaden sounds.
Another relatively cheap option to improve the overall sound absorbency of your room is to simply layer drywall on top of itself to create a super-absorbent sandwich of material, which is highly effective at deadening sound waves.
Layers are great for reducing vibrations, and if these layers are affixed using acoustic sealants like Green Glue, absorbency is greatly increased.
This technique can also be applied to create what is known as a window plug – essentially a measured chunk of layered drywall that can be inserted into the walls over windows to stop leakage through the glass and tiny cracks.
Sound Deadening Paint
Sound absorbent paints can be a great way to increase soundproofing for very little cost. While these products’ overall sound absorbency rating isn’t that high, they are cheap, easy to apply, and might just be that little extra you need to get your room fully soundproofed.
If making a window plug is beyond your DIY skills, or if you have a limited supply of drywall, you might want to consider something as simple as an extra pair of curtains. Not just any curtains, though – soundproofing curtains.
These are made of a highly dense weave of thick fabrics and work wonders when they entirely cover the window or door they’re used on.
While they are obviously not as effective as some other methods, largely due to the fact that they can’t become airtight, they can be a great addition to use on top of other methods, and they’re not too expensive either.
Soft Materials – Carpets and Rugs
In general, the more soft and absorbent materials you can get in the room you’re trying to soundproof, the better. Unlike hard materials, soft materials will soak up and deaden sound waves instead of reflecting them, thus decreasing travel and vibration.
This is easy, cheap, and can make a huge difference. Simply layer rugs on top of carpets, fix them to walls, and increase the amount of soft materials (cushions, blankets, etc.) you have lying around in the room. This will all help to absorb sound waves.
Baffles are a great way to deaden sound, particularly in a larger room. They consist of panels hung vertically from the ceiling. The panels are usually made of hardened fiberglass or other acoustic materials, and they work by absorbing sound and converting it to minuscule amounts of thermal energy.
Though they are not exactly on the cheap end of things, they are incredibly effective at soundproofing large spaces and rooms with high ceilings and can also look quite attractive too.
Soundproofing sounds like it could be very difficult and expensive, especially if you have no idea what you’re doing and plan on doing all the work yourself. But, like all DIY projects, doing things yourself allows you to experiment and learn as you go. Plus, you’re not bound by the expensive materials a contractor may use.
Depending on the reason behind your soundproofing journey, you might find simply putting a layer of MLV under the carpet and hanging some soundproofing curtains is enough. Alternatively, you might find you need to decouple the whole room and fill every single cavity with expanding sound-absorbing foam.