How to Select Acoustic Foam

Feb. 15, 2011 - PRLog -- While there are a variety of foam panels available in today's market, mostly at the click of a mouse, there are as many missteps that buyers can make in their selection process.   Picking the wrong foam can prove costly, even dangerous, if more care isn't taken in determining the right product choice for the right application.

The first distinction you should make is between acoustic and non-acoustic foam.   Some foam panels are closed cell, much like styrofoam, while others are open pore.   Open pores allow energy to enter into the foam, each individual pore vibrates like a tuning fork and converts sound wave energy into kinetic energy, which is nothing more than low grade heat.   Closed cell foam, however, can't accept the incoming sound wave, can't produce vibrations, and won't absorb echo.   The first check on your list should be to ensure that the foam in question is open cell.  Do not use styrofoam to absorb sound.

The second decision you should make is the fire code.   Open cell polyurethane foam is class B fire rated, while open cell melamine foam is class A fire rated.   If your noise source is near high heat or open flame, use melamine foam.   If your noise source is a loud commercial venue filled with echo. do not use polyurethane foam as it won't meet the fire codes.   If you are a restaurant owner, hospital, school, church or museum, do not accept foams that are not class A fire rated.

Many online suppliers advertise their foam as "fire retardent".   This could mean many things, but typically does not mean it is meant for use in a Class A fire rated building.   Fire retardent foam might mean it passes a test called the UL94 HF-1 test for self extinguishing.   Fire retardent foam that meets this test will self extinguish within 2 seconds, but will still not be class A fire rated.

Along with foam selection based on open vs closed, and Class B vs Class A, even more care should be given to the thickness of the panel.   If you buy thin panels, they won't absorb low bass tones.   While one supplier might push 2" thick material due to lower price points, if the buyer is a drummer, he's throwing good money away.    The thicker you go with your panels, the more aggressive they work to absorb low bass frequency noise.   Do not let the price point force your decision into thinner, less effective foam panels if your noise source is low bass frequency noise.

The key to the success of any foam treatment will determined by quantities introduced into a room, not where they are located.   Be sure you are targeting appropriate square foot totals for your treatment.   Placing one or two panels behind a loud sound source, such as a speaker, will do little to improve the acoustics in a room.   You need to be more aggressive with your coverage.    For drum rooms, target 70% wall coverage with 4" thick foam panels.  For vocal booths, target 50% wall coverage with 2" thick material.    For a band room, target melamine foam, for your garage band, target polyurethane foam.

For more help in determining the correct purchase for your acoustic foam, one recommendation is to purchase the material from a soundproofing supplier that has more than just foam on their website.   The reason being, foam suppliers only are limited to brand names that don't allow them to stretch your product options, and many times there are non-foam products for less than can also mitigate noise.   Also, seek soundproofing suppliers that date back 20 years with long, healthy track records.   They have the experience you can rely on more than the new websites that have limited experience targeting the right product for the right treatment.

Acoustic foam panels are a great product for lowering echoes in a room, but one final point.   If your goal is to sound isolate one room's noise from the next, put the foam down and target barrier products that are designed to block, not absorb, the sound from bleeding through your wall.   Foam does not block sound, don't be misled when shopping for acoustic foam.

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NetWell Noise Control supplies a variety of soundproofing treatments and related acoustical products for noise reduction and enhanced room acoustics. Free acoustical consulting for sound treatments in most any residential, commercial or industrial venue.