I love soundproofing because the results are dramatic and thus immediately rewarding. Perhaps the most rewarding of all soundproofing projects is soundproofing a movie theater. Part of why movies are so interesting is because their soundtracks not only contain many unusual, not-often-heard sounds, like explosions and gunfire, but they are loud, and meant to be. It’s hard to say whether the visual is more important than the audio in films, but it is clear that without an equally-impressive soundtrack, the experience would be much less, and just as you need an impressive projector to show the visual, you need an impressive audio system to play the soundtrack. With an impressive audio system, you need impressive soundproofing and sound control to keep it contained and controlled.
In this article, I will discuss why soundproofing movie theaters is actually quite challenging and how we go about meeting that challenge with an understanding of wall, floor, and ceiling assemblies to select the right soundproofing materials and techniques to get the job done.
Why Movie Theaters are a Challenge to Soundproof
What makes soundproofing movie theaters intriguing to me is because it is a challenge. The reason for this is the low sounds found in soundtracks, like explosions and gunfire or even a bass-heavy musical score, and how loud they are played in the theater. Low frequencies are harder to soundproof for, and certainly when played unusually loud, like in a movie theater.
If there were only one theater room then it wouldn’t be much of a problem, but movie theaters typically have many theaters, if not dozens, each one potentially pumping out seriously loud, low-end frequencies. If an action movie is playing in the theater adjacent to the one you’re in watching a quiet drama and the wall isn’t properly soundproofed, your experience will surely be disrupted. The goal for movie theaters then is to properly soundproof each theater so that adjacent theaters can be sonically independent.
Utilizing Mass and/or Decoupling to Wrangle Low Frequencies
After helping many theater owners find the right soundproofing solution for their projects, I’ve realized that they understand one of the key components of soundproofing, but not the other. When we talk about soundproofing, what we’re trying to do is block the sound. We can make a safe assumption that the thicker and denser the wall, the less sound will travel. If for example our walls are made of concrete instead of wood studs and drywall, the concrete wall will block more of the sound because of its mass. It would follow that selecting theater walls to be made from concrete – whether CMU, ICF, or related methods – would take care of the soundproofing issue without further ado.
When you’re trying to block low frequencies, however, we not only have to concern ourselves with mass, but also decoupling. When a loud, low frequency hits a concrete wall, it’s true that it will block much of the frequency spectrum because of its mass, but the low frequency wavelengths will still vibrate through the concrete and carry on beyond to anything the concrete is physically connected to.
What we need to do to attenuate low frequencies is decouple the wall, meaning create a separation within so that whatever doesn’t get absorbed by the concrete will sputter out as it crosses an air gap. Decoupling can be achieved in a number of ways, the most expensive of which is to build a double wall with an air gap between. As low frequencies pass a layer of CMU and reach an air gap, this gap in the concrete will significantly reduce the sound wave before it has to pass the second wall of CMU. By decoupling the concrete and adding space in-between, we can take care of the energy of low frequencies.
That said, building double walls, whether in a new build or renovating, is neither cheap nor time effective. A more feasible solution is to utilize soundproofing materials to decouple, such as our AudioSeal® Mass Loaded Vinyl (MLV) Soundproofing Barrier. By crafting a wall assembly with soundproofing materials, you may even be able to use drywall and studs to further lessen construction costs if using concrete methods.
Soundproofing a Wall (Wall Assembly Examples)
In the diagram above, AudioSeal® Mass Loaded Vinyl (MLV) Soundproofing Barrier is utilized alongside Green Glue Damping Compound with a double layer of drywall to create significant soundproofing capability.
When it comes to movie theaters and looking to block those tricky low frequencies, the implementation on the right is even better. Utilizing Resilient Sound Isolation Clips and a furring hat channel, an air gap is created between the drywall assembly and the studs that allows the low end energy to dissipate before reaching the actual wall.
This assembly method is my favorite, especially because it makes renovation far less complex and expensive than rebuilding an entire wall with concrete. It is also my go-to suggestion for home theater soundproofing as well as commercial, because it simply requires the current drywall to be removed and new drywall with the soundproofing materials installed. While that’s certainly more work than just hanging something on the wall, I’ve yet to hear from an unhappy customer that implemented it, considering the results. Especially in home theaters, the same method can be applied to the ceiling for complete soundproofing.
Soundproofing is Complete, Now Let’s Control the Sound
Often confused, soundproofing and sound control are two very different things, but both are equally important to a properly acoustically treated space. A soundproofed movie theater is our foundation while excellent sound control is how we craft a great experience. Again, our issue with movie theaters is wrangling that powerful low end, and we certainly do not want echo and reverberation within the movie theater to have a detrimental effect to the sonic experience. In order to control these, what we need to employ are sound control materials to “filter” the sound so that it sounds like it was meant to when designed.
One of my favorites for movie theaters is our Black Theater Board. The fiberglass board features a black scrim facing with low light reflectivity that makes it ideal for use in theater front ends and exposed ceilings.
Another fantastic option is our workhorse, AlphaSorb® Fabric Wrapped Acoustic Panels. Equally adept at mastering reverb and echo, these panels are offered in a variety of acoustic fabrics to meet functional and aesthetic needs. I often suggest utilizing black theater board in the front of theaters and in the ceiling, due to the low light reflectivity, while employing AlphaSorb® acoustic panels on the walls.
Soundproof Your Movie Theater Correctly with Proper Materials and Expert Guidance
No matter whether you are building a new commercial movie theater or even just one at home, soundproofing is a necessity. At Acoustical Solutions, we have helped countless theater owners find the right soundproofing solutions for their unique situation in a manner that matches their timelines and budgetary constraints.
Please give me a call today and we can discuss your specific circumstance and develop the plan and materials necessary to get you soundproofed as soon as possible!
To learn more about how Acoustical Solutions can solve your noise control problems, use our contact form, call one of our Acoustical Sales Consultants at (800) 782-5742, or visit us on the web at acousticalsolutions.com.
