Foam grades & types
Blog article: What is acoustic foam
Are you a musician? Music teacher? Podcaster? Youtuber? Freelance voice over artist? If so, chances are you have or would like to have a professional space which offers the best acoustic environment. Acoustic foam can be an excellent way to prepare such a space.
Even if you don't do any recording, but are an avid listener (e.g. you have a top of the range sound system and/or home cinema system) you could benefit from preparing your space with an array of acoustic foam products to get the best out of your listening environment.
Why bother with acoustic foam?
You may be wondering, does it really matter? There are several factors which can interfere with how sound is experienced in a room (either if you are trying to make a good recording or just after the best listening experience) such as:
Sound reflects off of surfaces, furniture and other objects in a room. The degree to which the sound is reflected depends on the nature of these surfaces (e.g. a smooth, flat surface will reflect more sound, while softer surfaces will absorb some or all of the sound). This is why you will notice much less sound reflection in a room containing various soft furnishings, carpets and curtains. Acoustic foam absorbs sounds rather than allowing them to be reflected.
Reverberation is when sound persists in a space after it is produced, due to being reflected off of the various surfaces in the room, often multiple times until the reflections eventually fade. Acoustic foam can reduce this by absorbing the sounds before they are reflected in the first place.
An echo is when the reflection of the original sound arrives at a listeners ear (or a recording device) shortly after the original sound is heard/recorded. The amount of time between hearing the original sound and any echoes depends on how far away the reflecting surface is. As with reflections and reverberations, acoustic foam can prevent echoes by stopping the reflections that would produce them.
A flutter echo is when sound reflects repeatedly between parallel surfaces, often for several seconds (depending on the size of the space and type of surfaces). Acoustic foam is ideal here, as treating one or both parallel surfaces will remove flutter echoes.
So now you know what kind of problems acoustic foam can solve, let's have a look at the types of acoustic foam that are commercially available and how they are applied:
Tiles & panels - example
Tiles and panels can be very convenient, particularly if they are self-adhesive, you can use these to treat specific areas which are particularly problematic for reflections, flutter echoes etc.
Bass traps - example
These are wedge shaped blocks of foam that fit neatly into corners, you can also fit a few together in corners of rooms. They tend to be good for absorbing low frequency sounds (hence the name).
Sheets - example
Sheets are convenient and can be purchased in rolls of specific sizes which can then be cut to fit whichever size surface you are treating.
Cut to size - example
Acoustic foam can also be cut to your required size and shape, as with other foam types.
Convoluted & flat shapes
All of the above foam types can be purchased in convoluted styles (e.g. the typical "egg crate" type pattern, or pyramid pattern) or with a flat surface. Convoluted surfaces are designed to absorb more sound than flat surfaces.
Here is a good example of how acoustic foam can be applied in a home studio setting, notice how "flat" the sounds seem after the entire room has been treated: https://www.youtube.com/watch?v=yu8uUV_AuVY