So you finally have everything set up the way you want it; you mounted your screen the perfect height, you were able to afford the projector you’ve been eyeing for the last month, you calibrated your surround sound levels perfectly, and now you’re ready to sit back and enjoy, but you hear a knocking on the door. Your heart drops.
It’s your wife. She keeps complaining that “it’s too noisy.” What did she expect? We know this feeling, and it’s not a good one. Soundproofing your Home Theater / Man Cave is an important step to making sure you’re going to be able enjoy all your hard work and money spent. There are a few important steps into understanding how to successfully soundproof your home theater without going overboard and breaking the bank.
Here’s The Idea
To understand what level of soundproofing you will need for your Home Theater, it is important to first understand how many dB’s (decibels) your home theater puts out, and by how many dB’s it will need to be reduced by in order to prevent your wife from yelling at you or your neighbors from calling the police.
So first, let’s understand dB’s. Let’s go over some examples to get a clearer picture (or sound) of what we’re working with so we can understand how much soundproofing we will need to do. Take a look at the chart below (inspired by Practical Home Theater Guide) :
Sound to Average dB
Now that we understand which sounds produce which levels of dB’s, we can begin to understand what kind of STC (Sound transmission class) rating we will want to achieve in order to successfully soundproof our home theater on a budget.
STC refers to the amount of sound transmission that is reduced by any given wall or ceiling. An average American residential wall has an STC rating of around 30-35 dB’s, meaning that it can reduce any given sound by 30-35 dB’s on average.
So if your Home Theater is pumping out 90 dB’s while watching Hacksaw Ridge and you haven’t done any soundproofing, the room next door is going to be experiencing about 70 dB (100 dB - 30 dB = 70 dB). That's like standing next to a diesel truck!
The standard American drywall and 2x4 stud setup will only reduce the sound by a little bit, so in many cases, additional soundproofing is necessary.
Now that we understand dB’s and STC, we can begin to look at which kinds of soundproofing will be necessary for your Home Theater. Some easy tweaks may do the trick, or some retrofitting may be necessary. Let’s take a look!
Understanding Your Home Theater
Not every Home Theater is built equally, and therefore you will have to decide what kind of strategy you will need in order to successfully soundproof your home theater. Take this into consideration; some people have very large homes where space is a abundant, and soundproofing isn’t as necessary.
Some people live in close quarters, where in adjacent rooms, wives and children are sleeping, or pesky neighbors are ready to call and make a complaint at any given moment. Keep in mind what your environment you will be building your home theater in, and we will walk you through how much each soundproofing technique will increase the STC of your theater.
Quick And Easy Soundproofing Hacks
Now, if you have a modest audio setup, you may be able to get away with some cheap home theater soundproofing methods. We’ll go through the most popular quick and easy hacks and provide an accurate estimation of how many dB’s it will knock off your bottom line.
Using weather-stripping foam tape and installing a door sweep to the doorway or entrance to the home theater or media room can help a bit. Foam tape around the doorframe and a door sweep will help keep sound from escaping through the cracks and thus reduce that amount of sound that is transmitted into other rooms.
The same idea goes for any other openings in the room, if you can seal them, do it, it will help more than you know. This can help reduce sound transmission by 2-4 dB.
Another quick hack lies within the ability of reduces the amount of bass that is pumped throughout the house. Place your subwoofer on a 2” thick piece of foam or rubber so it can’t travel through the studs and joists in your home as easily. This will help a bit, and hopefully you can see a 2-5 dB reduction.
Things like bass traps and acoustic panels won’t really help reduce the amount of dB’s that are transmitted into adjacent rooms, but rather improve the acoustics within the room. You can learn more about bass traps and what they do here.
How To Properly Soundproof A Home Theater
So now we understand decibels, STC, and how to implement the quick and easy soundproofing hacks, but what if your Home Theater is pumping out 100 dB and the kids are in the next room trying to sleep? You’re going to need to take further action. You’ll either need to retrofit an existing room, or be sure to properly build your home theater room when your home is being built. Here are the 3 most important concepts to properly soundproofing a Home Theater.
3 Core Soundproofing Concepts: Mass, Damping and Decoupling
1. Mass: Adding mass is the most common and least successful way (unless done properly) to soundproof a home theater. Adding mass include things like adding additional layers of drywall to improve your STC. Although this will help, it will only bring the sound transmission down about 3-4 dB’s.
2. Damping: The concept behind damping is simple, if you can dampen the vibrations that move throughout the studs and joists in the home, you can greatly reduce the STC rating of your home theater walls. Thanks to new technology, there are new sound-engineered drywall brands with viscoelastic compounds that really do a good job of increasing the STC rating of your home theater walls and reduce the amount of sound transmitted to adjacent rooms. Adding this type of drywall can boost your STC rating from 34 dB to up to 51! Not bad, right?
Adding mass along with the drywall is another way to further increase an STC rating by a few dB’s of your Home Theater walls. Using products like AcoustikBlok on the walls and ceiling of your home theater can really help!
3. Decoupling: Installing sound-engineered drywall and adding a vinyl layer definitely helps, but fails to fix the real problem. The real reason why sound (mostly bass) is transmitted from your home theater to adjacent rooms is due to the studs and joists in your home. The studs and joists that keep your home theater up are connected with every other stud and joist throughout your home. Thus, sound travels throughout the entire home. So how do we fix this? Decoupling is the only true way to fix this issue.
Known as a “floating room” or a “floating wall,” decoupling your walls will literally create a room within a room. There will be the original wall, 2x4 studs and standard drywall, then a 1” gap fully separating the two walls, then the new decoupled wall. The decoupled wall will have 2x4 framing, an optional layer of ⅝” plywood, your AcousticBlok vinyl mass, and then the acoustically-engineered drywall.
This encompasses each method of soundproofing and will provide your Home Theater the best type of soundproofing DIY can offer. This type of soundproofing would bring your walls from the standard 34 STC rating to 60-70 plus, depending on how well you build it.
For more information on these three core concepts, be sure to check out Sound Isolation Company!
Remember, if your Home Theater is putting out 100 dB and your walls have an STC rating of roughly 65, adjacent rooms will experience a quiet room, or “library” feel.
Putting in the extra time and effort can really go a long way!
Whether you are building a new home or retrofitting an old one, following these points will help you got from 0 to soundproof:
- Clear everything out of the room and remove drywall from both sides. This step gets very messy and dusty.
- After removing the drywall and cleaning up your space, remember to insulate and openings and apply fireproof putty to any outlets in the room. Take advantage of any chance you have now to get rid of these openings.
- Bonus Tip: Pick up some sound isolation clips from Pac International and install them to the 2 x 4 studs. You can then mount your plywood or drywall on the clips and enjoy a higher STC rating.
- If you decide against adding mass and putting a vinyl barrier, we would recommend that you use Green Glue damping on the drywall or plywood. Either apply the Green Glue to the plywood before putting on the drywall or apply the Green Glue in between layers of drywall if you wish to use two layers of drywall. This will help with damping. Acoustical Solutions has more great product recommendations for Home Theater soundproofing.
- Depending on how dedicated you are, your newly soundproof walls will look something like this; 2 x 4 studs, ⅝” plywood, Green Glue, optional vinyl barrier, and your sound engineered drywall. Depending on how well you soundproof your walls, if you follow these steps you can depend on going from a 34 STC rating to anywhere from a 60-68 STC rating! Not bad, right?
Now you just need to spackle and sand the surfaces, plug up any holes, paint, and clean up. The hard work is over (for the most part) and you can now focus on the techy stuff.
In the world of do it yourself, this DIY home theater soundproofing guide will truly help you get the results you want and need to really enjoy your audio equipment without the interruptions.
Now you have the Home Theater room of your dreams, you can sit back and crank up those new speakers you bought and you won’t have to worry about the wife coming in and shutting it down!