The importance of good acoustics in a home theater room cannot be stressed enough. Achieving that perfect balance of sound can really turn every home theater into a cinema. There is a misconception that sound absorption is the same as soundproofing.
To clear this up, absorption is one of the elements of soundproofing. So, while the panels on your home theater walls may give you aural pleasure, they do not stop the sound from escaping or entering your room. Soundproofing has more to do with materials in your walls or on your floors that trap the sound in and keep undesired sounds out and is paramount for two reasons. You deserve the experience of uninterrupted sonic quality, but your neighbour or people outside your home theater room shouldn’t be subjected to the noise that’s emitted from it.
When it comes to soundproofing a room, it is best to understand the difference between the two types of sound that cause interference; airborne sound and structure-borne sound. Airborne sound, as the name suggests, is sound that reaches us by air. Structure-borne sound is the result of vibrations from connected materials in our space. This could be a door banging, or something being dropped on the floor. This sound travels faster than airborne sound and tends to be mostly in the low-frequency range. Most sounds that we hear are a combination of both airborne and structure-borne sound. Before you embark on your project, consider this:
- What is the source of the sound?
- The entry point – knowing where the sound enters your room will help in determining how best to treat it. Windows are often the main culprits, but this could also be a door or an entire wall. And finally,
- The reflection point – as sound enters a room, it reflects back at the same angle of entry.
Identifying these touchpoints is key, and below we will see how to avoid living in an echo chamber by applying these for basic methods:
Adding Mass – all solid materials with thickness and density impede the transmission of sound and reduce the vibration and reflection of higher frequencies. Adding items of furniture against your walls might help a bit, but this will do nothing to control impact sound.
Damping compounds help to reduce the vibration of lower frequencies. They’re most effective when placed between two hard surfaces, which normally vibrate when hit by sound. Instead of rubbing against each other, these panels will vibrate against the compound, thereby converting sound energy into heat, literally stopping sounds in their tracks. Products such as Green Glue or silicone caulk are excellent additions when adding mass such as drywall.
Decoupling, although one of the most effective ways to reduce the transmission of sound through the structure of a building, is best done during the construction of your room. While it can be done after, it involves the removal of your existing drywall, floors or ceilings. I know that you’re capable, but I would suggest that you leave this to the professionals or might just end up with a bigger problem.
Absorption can be used used to muffle sound, but as I’ve mentioned, it is a soundproofing tool that cannot stand alone, and therefore works best when used with other methods.
Which Soundproof Material is Best for Home Theaters?
Before you’re stuck with a grudge purchase, here’s what to look for in soundproofing materials.
Mass helps to absorb sound waves, so the first thing to look for is thickness and density. The sound transmission class is a rating applied to most soundproofing materials, so the higher the rating, the better. The biggest issue with flooring, and especially hardwood flooring, is impact noise. There are times when you can barely creep to the fridge at midnight without waking the neighbors. The impact insulation class rating gives an indication of how good a material is at solving this problem, and again, the higher the rating, the better.
With the basics in the bag, let’s get down to the nitty-gritty. The following materials are ideal options when it comes to soundproofing:
Mass Loaded Vinyl Sound Barriers
These top the charts because of their practicality and effectiveness. It can be used on your floors, or between your dry walls, without adding unnecessary bulk.
Acoustic Mineral Insulation
Most homes include some sort of insulation in the walls and ceilings when they’re built. Although the primary purpose is to prevent air from seeping through, and not to soundproof, this insulation serves a dual purpose in also preventing sound from traveling through. This is a cost-saver if you’re building a home theater from scratch, but a bit of a snag if your home is already built. You will need to remove your drywall to get to the studs underneath and place your insulation into the spaces between.
Green Glue Soundproofing Compound
This is the cake topper if you’re using the damping method. Not only does it work to soundproof, but it also works as an adhesive, meaning no screws are necessary.
Resilient Sound Channels
These are metal sheets that can be added to your walls and ceilings and can be used if you opt for the decoupling method. They are effective at improving noise blocking in your walls.
Using Sealants, Caulking And Silicone.
Acoustic caulk or sealant is reserved for your final touches. Any minor cracks can be filled with caulking. This may help remove some sound but it also helps improve the aesthetics. Cracks and separations can be unsightly so when they are caulked it makes your work look refined and finished. A good choice is a sealant combined with caulk and silicone. Silicone is for the flexibility and the caulk allows paint to adhere to it better. Although I referred to it as acoustic sealants its also referred to as caulking and silicone.
Home Theater Soundproofing Panels
As discussed earlier, absorption is just an element of soundproofing, so these panels will not prevent sound from coming in or going out. Acoustic foam or panels offer absorption qualities and are therefore more effective at improving your audio performance than they are at blocking out sound. They come in a variety of shapes, but what matters again is thickness, and of course, position. You can learn about acoustic treatments here.
Zero Sound Drywall
Soundproof drywall has a higher transmission class than other types of drywall. It ìs a very popular paneling option, and with due reason. It’s is easy to install, readily available and relatively cheap. If you’re pulling out all the stops and remodeling or building a home theater room from scratch, QuietRock is the best but more expensive option, with better soundproofing performance than drywall. It can be installed over drywall, but with screws rather than adhesive as this will affect its performance. It is available in different thicknesses, and when it comes to soundproofing, thicker is always better. Remember that drywall, although cheaper, will also work better with dampening materials like Green glue.
They are thicker, denser and heavier – the perfect recipe for soundproofing – except that they’re not very attractive.
Soundproof curtains may be a little less effective than soundproof blankets, but they certainly make up for it in the aesthetic department.
The best curtains for those niggly windows that still persist in stepping on your last nerve are 100% blackout and soundproof curtains. The “blackout”, not to be confused with block out, which is completely ineffective, basically means that if you shine a light on one side, you will not see it on the other side. The soundproof feature lies in the middle of the three layers of cloth that make up these curtains, which are multi-functional, and can be used to cover windows, walls, doors, and even a cupboard if necessary. These may not be as effective at dampening low-frequency sounds, but they do work well on high frequencies and the bonus is that they add to the ambience of your room. And, hey, if you want the best of both worlds, you always have the option of draping curtains over the ugly soundproof blanket.
While carpets aren’t necessarily soundproof on their own, throwing a thick, plush rug over your floor is an ideal way of reducing reflection that bounces off the floor. To make it soundproof, you may want to consider one of the following options:
- Add a layer of soundproof carpet underlay.
- Mass loaded vinyl is a definite favorite in the soundproofing world. Vinyl is preferred because, although it’s thin, its density is perfect for sound absorption. It’s perfect to use under carpets because it’s so thin.
- Sound deadening floor insulation – Again, this is a dense material that goes under your flooring, keeping echoes at bay
- Acoustic floor tiles – These work in the same way as acoustic wall panels and will help to reduce echo and reverberation.
Seal Windows And Doors
Windows and doors are about the toughest areas to soundproof. It can seem a bit overwhelming, especially when an element is made up of other elements. Your windows, for instance, would require different treatments for the glass, the frame and of course the cracks around it. Weatherstripping can easily take care of sealing your door and window frames, and door sweeps or draft stoppers ( better suited to interior doors) are excellent in sealing the gap at the bottom of your door. There is no other way around it. I mean, you have to be able to get in and out.
Windows are the main causes of rattles from the outside, and the ideal choice would be to replace these with double panes, but it is a rather expensive project. Well, there is a way to thicken the glass slightly and reduce vibrations without leaving a hole in your pocket – plastic sound dampening film. This will decrease the rattle and keep the nosey neighbours out. Whether due to poor installation or wear and tear, both windows and doors tend to develop cracks around them over time. These cracks again cause air gaps, and we know that air in this case is the enemy. Acoustic caulk or sealant is a fast but reliable way of fixing these little irks.
Where Can I Buy Soundproofing Materials
Soundproofing materials are very easy to get your hands on, and places like The Home Depot, Lowes and Menards will leave you spoilt for choice. With all the options available, the only thing your better half will have to nag about is the amount of money you’ve spent.
How To Make A Soundproof Room For A Home Theater
I think you should have no problem soundproofing your home theater. This should be a good starting point. Although totally soundproofing your home theater 100 percent may be close to impossible unless you live in a totally sealed concrete structure. These applications should help you get most of that seeping sound out of your neighbors home or other spaces of your own home.