The 10 Most Common Questions About Acoustics

1. Do acoustic panels help with soundproofing?

In a nutshell, no. Understandably, this is a confusing one, but there is a huge difference between acoustic treatment and soundproofing.

Acoustic Panels, Bass Traps, and Diffusers are all acoustic treatments used to control the acoustics within a space (e.g., reducing reverb, echo, bass trapping).

Soundproofing refers to isolating a room from its surroundings or to stop the transmission of sound through one wall to the next. Soundproofing almost always requires some degree of construction to build heavy new structures that are decoupled from the other walls and ceilings.

2. What are bass traps?

Bass traps are low-frequency, sound-absorbing devices. They are used to absorb the very large waveforms created by low frequencies.

Without effectively absorbing low frequencies, rooms have massive dips and peaks in their frequency response.

Bass traps come in a few varieties, the most common ones are porous absorbers, membrane absorbers, and Helmholtz resonators.

3. What are room modes?

Room modes are natural resonances that occur when speakers or a sound source excite a room at frequencies with wavelengths equal to the room dimensions.

This leads to standing waves that cause large distortions to the frequency response of the room, emphasizing some sounds while masking others, and causing very uneven decay times. Ultimately this leaves you with an inconsistent and undefined foundation for your monitoring system.

4. What are sound diffusers?

Sound diffusers, more commonly known as Diffusers, are acoustic devices used to diffuse or scatter sound waves to prevent specular reflections.

Simply put, diffusers break up sound waves and re-distribute the reflected energy more evenly.

Diffusers are most commonly used in spaces where reducing acoustic energy (as would be done with an acoustic panel) is not desired (e.g., tracking rooms, concert halls, listening rooms).

5. I have extra acoustic foam, can I use that in my room?

Not all acoustic foams are created equal but for the most part, the answer is no. The cheap acoustic foam with wedges or triangles does not have the required mass or depth to effectively absorb mid or low frequencies. If you are only looking to absorb frequencies above 2,000Hz though, go for it.

6. How much acoustic treatment do I need?

This will vary drastically from room to room based on the use of the room and the desired soundscape. Recording studios have very different needs from restaurants and one restaurant will inevitably want a different sonic scape than another. If you need help figuring out what is needed for your space, fill out our Free Room Advice Form.

Here are some recommendations that can give you a ballpark sense of what is needed.

Home Studios: 30 to 60% of the walls and ceiling covered

Control Rooms: 50 to 75% of the walls and ceiling covered

Podcast Studios: 50 to 75% of the walls and ceiling covered

Restaurants: 35 to 45% of walls or ceiling covered

Offices: 20 to 50% of walls and ceiling covered

7. Where should I put my acoustic treatment?

This is another question where the answer will be very dependent on the space and the sonic goals for it.

For restaurant, office, and gym acoustics, the best option is to evenly distribute acoustic panels on the walls and ceilings. The more evenly distributed the treatment, the more efficient and effective it will be.

For recording studios, we need to break this down into two categories: For control rooms and home studios, you want to start by targeting the early reflections on the sidewalls, ceiling, and back wall. This will start to establish a reflection-free zone at the listening position. For tracking rooms, you will generally want to start with an even distribution of acoustic treatment. Often times this will consist of both absorption and diffusion.

If you need help figuring out where to put acoustic treatments in your space, fill out our Free Room Advice Form and we’ll be in touch.

8. What are sound barriers?

Sound barriers are materials or combinations of materials used to isolate a sound source or room. Typically, sound barriers are built into walls during the construction phase but there are some products that can be retrofitted on existing walls/structures.

In order to be an effective sound barrier across the frequency spectrum, these materials need to be very dense and heavy. Mass-loaded vinyl is commonly used in soundproofing applications as a sound barrier both in walls and as a floor underlayment. Two layers of drywall with Green Glue between them is another example of a common sound barrier used for soundproofing.

9. How do I Soundproof a door?

Soundproofing a door is a difficult task if you are hoping to stop any and all sound from getting through it. There are some acoustic doors that will get you close but they will cost you around $4,000 each.

Luckily most of the time, total isolation is not required, and you can build your own soundproof door with readily available products.

Our preferred DIY method is to use a solid wood core door and a door seal kit. The most important thing here is achieving an airtight seal all the way around the door when it is shut.

If you are framing out a new room, utilizing double doors is always the best practice. Use solid wood core doors for both and door seal kits. If you are on a budget, you can use an automatic door bottom and silicone door seal.

10. How do I soundproof a window?

First, are you blocking/covering/plugging a window, or do you want to preserve that precious natural light? If you no longer need a functional window or natural light, the cheapest and simplest option is to cover the window.

1. Build a frame 1.5” taller and wider than your window out of 6.5”x.75” boards.

2. Put weather stripping on the back of the frame to de-couple it from the wall and to provide an airtight seal.

3. Use Mass Loaded Vinyl to cover the inside of the frame. (This may need to be offset with furring strips so the frame fits over the window trim.)

4. Fill the frame with Mineral Wool or Owens Corning 703/705. Use 4” if possible but 2” will still help.

5. Wrap the frame with fabric.

This won’t completely eliminate outside noise, but it will drastically cut down on the sound transfer from outside to in and vice versa.

If you want to preserve the natural light, there are typically two options:

1. Replace the existing window with a double or triple-paned prefabricated window. Installed properly (acoustically sealed all the way around), you should be able to achieve an STC of 50 or 55 depending on whether you opt for a window that can open and close.

2. Add an additional pane of glass to the existing window structure. If going this route, be sure to use glass that is at least 3/8” thick, preferably thicker. When installing, use an acoustical sealant or non-hardening silicone caulk to both decouple the glass from the window frame and to provide an airtight seal.

If you need additional guidance reach out to us about our Consulting services.