FAQs - Acoustic Soundproofing Foam

FAQ (Frequently Asked Questions)

General Questions

Can the foam be cut to shape sizes on my design?

Yes. We suggest using a razor blade or utility knife to get the cleanest cut, but make sure to cut on a hard, flat surface or the foam may tear or cut unevenly.

What's the process for mounting acoustical foam to the subject matter?
We suggest using a spray adhesive meant for strength of holding foam, or liquid nails from a home construction store.

Temporary Mount: For a temporary mount, lightly use adhesive and mount.

Permanent Mount: For a permanent mount, make sure to generously spray the adhesive coating on the foam without saturating it then apply it to the mounting surface exactly where you want it to permanently be. Make sure the adhesive is evenly placed and sticky before mounting to the surface. Hold it in place for a couple minutes before applying the next piece.


When using spray adhesive to mount foam

  • Map out your foam positioning/layout ahead of time so you know where the foam will go and how it will fit proper within your design mounting area.
  • Use a cloth, towel, cardboard or papers under the area you'll be spraying so you don't get the sticky substance on the surrounding area.
  • Make sure wherever you're mounting is clean, smooth and there is no dirt or grime on it.

Either way, make sure to wash the surface first and let it ample time to dry and/or wipe the area clean with a towel following the washing.

  • Make sure the room is a constant 71° F (21° C) for best continuous hold with adhesive. Keep this degrees constant for about 3 days for best results. 
  • Mounting to Textured Ceilings or wallpaper will not allow adhesive to hold strength and often times loses grip and falls. Make sure to sand the area first for best results.

For permanent mounting to surface:

  • Apply adhesive to both the foam and the surface you'll mounting it to
  • Within about 6-10 seconds the adhesive will become sticky
  • Be careful when placing your foam to ensure it is where you want it to permanently be then hold it firm for a couple minutes. It usually takes about 15-30 seconds for it to start bonding well. This should hold it in place, but we recommend never pulling or tugging at any piece as it could either become unmounted, tear, rip or damage the surface it's mounted to.

For mounting foam together:

  • Apply adhesive to both pieces of foam
  • Within about 6-10 seconds the adhesive will become sticky
  • Place both pieces firmly together very carefully
  • Give it about 10-12 minutes to allow bond to hold before doing any further manipulation or mounting with the foam.
  • *PLEASE NOTE*: When applying spray adhesive to your foam, it simply will not stay bonded to concrete, cinderblock or painted walls. If you have no other choice, it would be advised to use heavy-duty construction adhesive. This might cause the foam to be damaged permanently so we do not suggest this method if possible. It mounts much better to mount the foam to cardboard or plywood and then mounting the foam. Our spray adhesive will work great with substrate bonds.
  • If you need to mount to concrete, make sure to clean it well of loose particles, brush it, wash it and let it dry to clean off all loose particles before mounting. 
  • Keep in mind, no matter what method you use to mount your foam using adhesive, it may leave residue on the object you're mounting to. The stronger hold you hope to accomplish has a higher chance of tearing the foam when pulling away from the mounted subject later on after the bond hardens.
  • NOTE: We are not responsible for any damage whatsoever to your personal usage of this mounting product no matter where you use it. 

Is there any way to mount the foam without an adhesive compound?
Yes. You can use T-pins to mount directly to a wall or ceiling or you may also use a board (such as cardboard, plywood) and them mounting or hanging that to a well or from the ceiling.

Color Pack Variety Questions

May I make a variety color pack when ordering soundproofing foam?

No. However, we're more than happy to allow you to order one color per pack if it is an option on the product page. It is simply too hard to have a variety of colors in one pack. 

Acoustic Foam Questions

Will my foam be enough soundproofing to permanently stop sound from traveling through walls?

The acoustical foam that we sell can definitely help with dampening outside sounds behind doors and walls, however its main use is to improve the sound clarity in rooms, especially in recording studios. In example, if you had covered your four room walls and ceilings with our four inch thick foam, you would see about a 25%-30% noise reduction. To eliminate even more sounds, we would suggest using sound panels, (which we will be offering in the near future) or for extreme circumstances, you would want to build a room within a room which leaves a cushion of air space to deaden sound even further. 

For acoustical recording rooms, how much foam would I need?

Depending on how clear or "dead" you want the sound to be, most rooms start at 50%, especially if you are in a quiet area and/or have barriers in the room already such as carpets, furniture and objects in the room already absorbing sounds. Otherwise, about 50%-75% is the typical room for most musical styles other than jazz or classical which take far less foam. However, ADR rooms would be best utilized being fully sound treated, and in a lot of cases combo'd up with sound panels. 

Where should I mount my pyramid and wedge foam?
We suggest started at the top of the wall and working your way down. Ideally, you want to trap the area where you are recording so you can get a crisp, clean sound. Your feet won't be moving much so having no foam lower than the knees is often times ok. 

Pyramid foam can be mounted in any particular direction as it will split the sound frequencies on a simultaneous level. However, by rotating the triangle wedges at various angles, you can split up frequencies much more efficiently. The pyramid is better used for acoustic while triangle is better for lots of voice over, singing and dialogue. This is considered the "checkerboard" style in where it is rotated simultaneous for each wedge.

Where should I mount my bass traps?

The best place to mount your bass traps is in the top corner where the room meets the walls and one near the floor or halfway down the wall, even better so if it's equal to or above where the bass frequencies are emanating from. If you only have four, place them in the back corner ceiling unless it's higher than about 8-10 feet. It would be be wise to mount blocks in the corners with the bass traps placed next to them for maximum low frequency absorption.

You may want to consider male/female broadband absorbers for corners that aren't at a 90 degree angle. 

Please explain what "NRC" stands for.

NRC = Noise Reduction Coefficient. The two ways to find NRC of the material being graded is by two methods:

  1. Reverberation Room Method (ASTM C423) << Our graded method
  2. Impedance Tube Method (ASTM C384)

It's Graded by:

First, Around 72 feet of material is set flat against a floor in a reverberation chamber, which tends to typically use only hard concrete surfaces. Secondly, the absorption changes are measured by comparing by the room with the material in it versus and empty room. The octave ranges of 125Hz - 4000Hz are measured using Sabin absorption coefficients. The calculated average of the frequencies are graded at 250Hz, 500Hz, 1000Hz and 2000Hz respectively, which in turn is what the overall NRC rating is. Having a higher NRC rating means the materials can absorb more sound frequencies and materials with higher gradings tend to cost much more than those with lower gradings.

Acoustic Wedge & Foam NRC Ratings

The effectiveness of our foam's quality is measured by its NRC rating as seen below.

    125 Hz
    250 Hz
    500 Hz
    1000 Hz
    2000 Hz
    4000 Hz
    1" Wedge
    2" Wedge
    3" Wedge
    4" Wedge

    Please explain what "STC" stands for.

    STC = Sound Transmission Class. The method of generating this rating is by comparing the acoustic isolation of various materials. (ASTM E413) is the process to calculate an STC rating.

    Here's how the process works, one "source" room has a speaker and the "receiver" room has a microphone. Both rooms typically have a 9 foot opening. Sound is recorded in 1/3-octave bands from 125Hz-4000Hz using decibels. This is recorded and leveled with and without material in the rooms covering the open space.

    The difference in decibels is measured with "TL" (short for Transmission Loss).

    Finally, data from the transmission is drawn on a graph using Hz and dB measuring frequency and transmission loss. 

    The data of the transmission curve references to standardized STC curves. The STC rating stems from comparing the closest matching standardized curve to the transmission data curve. For requirements of a match, the reference curve cannot surpass transmission loss of more than 8 dB in any 1/3 octave band and the total of all the negative discrepancies cannot be more than 32. After matching up to the requirements, then the most similar matching reference curve at 500Hz is now the official STC of the graded material.

    Please understand that when you are contemplating which material to purchase, know that the field & lab measurements may sometimes vary from 1-5 STC depending on the particular application.

    DISCLAIMER: The suggestions that Dragon Acoustics offers are merely suggestions. Dragon Acoustics and it's employees always hope to offer the best advice with the most informative ways and prove to you how our products work for us, yet any advice we offer comes from our own experience and should not be substituted for that of an audio professional or by using your own judgement or that of the customer. When we offer suggestions, please understand each room being sound treated has too many variables to be the "exact same" every time, which may cause a different outcome to the end result of using our products matched with expectations.

    Questions - Fire Retardant Foam

    Your acoustical foam products are fire retardant, correct?

    Correct, all of our acoustic foam products are fire retardant, and you can view the fire rating within each products item description. We also provide more fire retardant information within our Data Sheet below. Fire retardants are imbued directly within the foam's formula. 

    Property Test Method Values
    Density (LB/Cubic Ft.) ASTM D 3574 1.2
    25% ILD (LB) ASTM D 3574 45
    Support Factor (65%/25% Min.) ASTM D 3574 1.90
    Tensile (PSI) Min. ASTM D 3574 13.0
    Elongation (%) Min. ASTM D 3574 200
    Tear (PPI) Min. ASTM D 3574 1.30
    Resiliency (%) Min. ASTM D 3574 35
    Fire Retardant Classification CA TB #117
    ASTM E84
    Class A (Self Extinguishing)
    Contains Fire Retardant Additives - - - Yes
    Contains NO PBDEs

    *The values shown are general values and we cannot legitimatize the accuracy of this information or products suitability for any specific reason. We do not offer warranty on our products. Buyer assumes all responsibility for any damage or loss which happened from the mishandling or misuse of the product whether it is done with our suggestions or not. Any statements we've mentioned about the ways to use this product are intended to as usage or recommended usage of the product for any sort of infringement or patent whatsoever.

    Why use acoustic foam instead of packing or bedding foam?

    The reason we suggest using acoustic foam is because it is custom designed to be functional as a sound-deadening product for specific uses and absorb specific frequencies and sound waves and they also have fire retardants imbued in them for safety. They are also cut in use designed specifically for the most typical types of rooms to soundproof, especially in sound studios.

    What if the foam is exposed to extreme heat or flame?

    It would merely smolder and smoke but it will not catch on fire. Once the flame is removed from the foam, the flame will simply die out.

    *Dragon Acoustics and it's employees do not recommend lighting or exposing any of our foam to flame, fire or extreme heat and/or performance of any testing on our products. If something happens, Dragon Acoustics cannot be held liable for injury, loss or other damage resulting in misuse of our products.

    In order to pass my building codes, what information must I have available?

    All of our foam products have been tested in accordance with ASTM E84 AND NFPA 255 for surface burning and meet the standard for "Class A/Class 1". This is the norm and most building codes accept this, but always check the requirements ahead of time to make sure before you install any acoustic foam purchased from us.

    What do you mean by "Class A/Class 1" when you are referring to retardant specs?

    The ASTM E84 test calculates the flame spread index and the other calculates the smoke developed index. The numbers entail whether the materials will be classified as Class A, Class B or Class C (IE 1, 2, 3). Class A entails the materials don't burn or smoke too much. Class B burns and smolders a little more than A but Class C burns a lot and produces more smoke than the previous two.