Common Soundproofing Mistakes to Avoid
Although there are aesthetic choices involved, soundproofing is much more a science than an art. Whether you’re approaching a small space with a DIY plan or overseeing large-scale venues, there are basic principles to follow—and mistakes to avoid—to ensure your investment pays off.
The way that the sound wave interacts with each interruption and surface involves many factors: material composition, density, shape, and much more. Selecting the right materials for the job, starting with an analysis of your space, and installing acoustic treatments properly are some of the most common aspects necessary to avoid bad soundproofing.
Overlooking Room Acoustics
Mistake #1 is skimping on a key preparation step for a soundproofing plan: reviewing your current room acoustics.
What issues are you trying to solve? Writing down a shopping list of soundproofing products before you figure out the current state of your space’s acoustics is time and money down the drain.
So, how do you identify your noise issues? Figure out:
- The source of the problem and type of noise
- Whether the noise is airborne (i.e., traffic) or structure-borne (i.e., plumbing)1
- The noise frequency (i.e., low hum from HVAC or machinery vs high frequency noise from human voices)
- Whether the background noise is from single or multiple directions
- The decibel level, frequency, and reverberation time of the noise within your space
- A sound map of dead spaces and louder zones
Your best plan is to work with an acoustic treatment professional to measure and map this information in each room or area of a large space. They’ll use specialized testing equipment and software such as:
- Sound pressure level (SPL) meter2
- Reverberation time (RT60) meter along with a tape measure and laser pointer
- Frequency response analysis
- Impulse response testing device
Depending on your acoustic measurements, you may need to soundproof for certain frequency ranges, for noises coming through windows or adjoining rooms, or for other specific parameters.
Choosing the Wrong Materials
Soundproofing isn’t a one-size-fits-all solution—choosing the right insulation material depends on your noise issues, goals, room acoustics, and materials already in place. Unless you’re starting from scratch with a new build, a soundproofing project starts with understanding your space’s construction and needs.
Regardless of your structure and goals, some soundproofing materials are always going in the “wrong” column. These items are either wholly or so nearly useless as to be a waste of energy to install:
- Mattresses
- Cardboard or chipboard
- Yoga mats, car mats, doormats, or rugs hung on walls * Add “carpet”
- Low-density foam
- Styrofoam or cardboard egg cartons
- Soundproof wallpaper or paint
One of the primary approaches to sound control is to create additional layers, but deciding what types of materials and placement to use requires knowing current construction details. Figure out your space’s:
- Construction materials used for the partition walls, roof, ceiling, and floors
- Placement of outlets, ducts, vents, and any other openings
- Type, amount, and placement of insulation
- Location and number of hollow-core doors and walls *Remove “hollow-core”
Your material choice will be based on different but overlapping acoustic objectives:
- Sound proofing – Creating an isolated, air-tight space like a recording studio
- Sound absorption – Soaking up noise with porous materials of varying density
- Noise level control – Manipulating sound with absorbers and diffusers
Selecting the right materials isn’t about piling on the maximum amount. For instance, if traffic noise is leaking loudly through a restaurant’s front windows, no amount of acoustic wall panels will block that noise pollution. Instead, a solution might combine:
- Soundproofing window inserts to reduce the noise source
- A blend of wall, ceiling, and floor soundproofing treatments to absorb and reduce the noise
- Acoustic door sealing kits on entry doors to close gaps and reduce incoming noise
Ignoring Flanking Paths
Soundproofing often considers what noise travels through solid surfaces like the walls separating adjoining rooms. Flanking noise refers to sounds that reach a room by an indirect path—and it’s too critical to ignore.
Even with beautifully soundproofed walls, if adjoining spaces have a range of small and medium gaps and open spaces between them, flanking noise will remain a major irritant. Flanking noise paths include:
- Back-to-back outlets or junction boxes in the same stud cavity3
- Open or poorly sealed doorways, walkways, or windows
- Ductwork
- Structural connections such as subflooring, stud walls, and ceiling joists
After identifying flanking noise pathways, you can address the problematic sources by:
- Adding sealants, insulation, caulking, and acoustic tape and fillers to all small gaps
- Installing heavy, solid-core interior doors with proper acoustic sealing
- Using a set of two doors with an airlock space between them rather than one door
- Ensuring doors close automatically
- Decoupling soundproofed interior surfaces from the structural skeleton
- Installing HVAC sound reduction products such as duct silencers, wrap, and liners
- Adding soffits to cover exposed ductwork
Misuse of Soundproofing Techniques
The best product in the world will be ineffective if it’s improperly installed. In addition to choosing the right products and techniques for the job, you’ll need to ensure they’re safely and correctly placed and installed in order to serve their purpose.
Use caution when selecting, planning, and installing these items in particular:
- Resilient channels – These flexible metal channels are used to separate drywall from wall studs. The decoupling dampens sound by reducing the ability of the sound wave to transmit from one surface to another. To work properly, resilient channels must be correctly sized and placed relative to studs, fitted between studs and drywall (not two sheets of drywall), the only surface to which drywall is anchored.
- RSIC – Resilient sound isolation clips (RSIC) are another method to decouple wall surfaces and interrupt sound transmission. Like resilient channels, they’re most successful when carefully spaced and installed by professionals who understand their use.
- Acoustic caulk and sealant – Don’t skip or skimp on this low-priced option. Just like a zip-locked storage bag is useless without taking the last step and actually zipping it closed, surface soundproofing treatments need to be combined with sealing the cracks, corners, edges, and gaps to get the job done.
Focusing on Noise Control vs. Soundproofing
There are some sounds you can control, but noise from neighbors, adjacent businesses, or highway traffic isn’t typically something you can negotiate effectively and permanently. Even if you’re dealing with utterly thoughtful people pleasers, a “noise detente” will fall apart with a shift in tenancy or individual needs and preferences.
Kindly worded requests and gentle diplomacy can be effective in trying to reduce noise levels or periods, but you’ll still be operating in a too-loud space if you skip soundproofing your domain.
Neglecting Professional Advice
Creating and implementing a soundproofing plan can strain your budget if you troubleshoot your space without professional help. Acoustics professionals can:
- Take scientific measurements of your space to map weaknesses and test solutions
- Correctly pair new soundproofing products with your current structural elements
- Guide you in no- and low-cost ways to redirect and absorb sound
Acoustics management at the detailed level is a scientific discipline, with multiple rating systems used to measure and classify spaces and materials:
- Sound transmission class (STC) product ratings related to noise penetration
- Sound absorption coefficients
- Impact insulation class (IIC) for floor and ceiling assemblies
- Decibels (dB) and A-weighted decibels (dBA)
- Noise reduction coefficient (NRC) ratings related to level of sound absorption4
Partnering with pros can ensure you don’t get trapped by marketing claims that don’t come true in your environment.
For example, a promise to reduce noise by a set amount may be based on a scientific study that tested the product in a structure with entirely different properties than yours. Digging into the details behind the ratings and understanding how soundproofing materials combine to a greater or lesser benefit is how professionals direct you to the best solution for your space and budget.
Relying on a Single Product
You probably don’t need acoustic panels spread out to cover every inch of your floors, ceilings, and walls. Effective soundproofing requires a mix of product types plus spatial arrangement techniques that complement each other.
Instead of one miracle product, your plan might include:
- Soft surfaces such as carpeting and fabric wall coverings
- Upholstered furniture arranged to break up large spaces
- Intermittent acoustical wall panels and drapes
- A mix of ceiling sound baffles, clouds, and acoustic tiles
- Decoupling key walls from underlying structures
- Insulation and sealing
The Critical Steps to Avoid These Mistakes
Don’t waste limited resources on an ill-planned soundproofing investment. Instead, engage a pro team to measure and analyze your space’s acoustics and construction before assisting with a soundproofing plan that incorporates:
- The right sound damping material and product blend for your space
- Solutions for flanking as well as direct-transfer noise sources
- Proper implementation and product installation
How Acoustical Surfaces Can Mistake-Proof Your Soundproofing Plan
Whether you’re starting from scratch or making corrections, Acoustical Surfaces is the right partner to manage your environment’s sound-related needs. From private homes to concert halls, we understand how to meet the acoustical goals of each specific location.
Our team can offer methods, tools, and products that fit your space and budget. We understand the mechanics of acoustics and how to absorb, block, and isolate sound and vibration.
Ready to learn more? Reach out today to work with the sound experts.
Sources:
- Whisper Room Inc. Soundproofing Mistakes and Myths. https://whisperroom.com/tips/soundproofing-mistakes-and-myths/
- Underground Talent. Room Acoustics: How to Test the Acoustics of Your Room? https://undergroundtalent.co.uk/room-acoustics-how-to-test-the-acoustics-of-your-room/
- Family Handyman. How to Soundproof a Room. https://www.familyhandyman.com/project/how-to-soundproof-a-room/
- The Spruce. How to Soundproof a Room or Apartment Affordably and Easily. https://www.thespruce.com/soundproof-your-room-or-apartment-4062945
