Acoustical insulation is designed to absorb as much sound as possible with as little sound reflection as possible. Acoustic insulation sold on our site comprises of Fiberglass and Mineral Wool insulation panels that are 24" x 48" sheets. The thicknesses that we have vary from 1" to 4" thick (Rule of Thumb: the thicker the panel the better absorption of low frequencies).
PLACEMENT OF PANELS: The placement of acoustic panels depends on the type of application. If this is for sound absorption of lower ambient noise or echoes in a restaurant or conference room the placement is not as important as the number of panels installed. Usually the walls or ceilings are fine for acoustic panels in these types of situations. These panels can be easily installed with our Acoustic Impaling Clips.
For sound studios and home theaters, the placement of acoustic panels is of much more importance. If bass speakers are being used, it is highly recommended that bass trap panels are installed in the two corners of the rooms facing the direction of the bass speakers (sub-woofers). Bass trap panels can be stacked to "cut" the entire corner or if only one panel is being used, they should be installed at the same height as the bass speakers. Bass Trap Panels can be easily installed with our Bass Trap Corner Brackets. For lower frequencies, you will want to build a panel that is atleast 4" thick. The 4" thick 4# density mineralwool board is a preferred option for corner bass traps.
The placement of non-bass trap acoustic panels are less critical, but it is always better to install them on the walls near the speaker's spot of first reflection. The first reflection is generally halfway between the speakers and the listener. For example, in a home theater the tv screen and speakers are on the same wall facing the couch which is in the back of the room. The spot of first reflection would be on both of the side walls and ceiling halfway between the couch and the tv and speakers. By absorbing the reflected sound, the listener will only hear the direct sound waves coming from the speakers and not the reflections as well.
HOW DO I KNOW WHAT TYPE OF ACOUSTIC INSULATION TO PURCHASE?
Most acoustic sites don't really go into details on what type of insulation you need or what thickness is appropriate. That's most likely because they only promote one type of insulation (the cheapest or easiest for them to use in their acoustic panels). To simplify this for our customers you can use the table below for the 7 acoustic insulation panels we sell.
CO-EFFICIENTS AT FREQUENCIES IN HZ
PANEL TYPE |
DENSITY
|
|
125 |
250 |
500 |
1000 |
2000 |
4000 |
NRC |
1" Fiberglass |
3# |
CLICK TO BUY |
.11 |
.28 |
.68 |
.90 |
.93 |
.96 |
.70 |
1-1/2" Fiberglass |
3# |
CLICK TO BUY |
.14 |
.57 |
.91 |
.99 |
.98 |
.97 |
.85 |
2" Fiberglass |
3# |
CLICK TO BUY |
.17 |
.86 |
1.14 |
1.07 |
1.02 |
.98 |
1.00
|
2" Fiberglass |
6# |
CLICK TO BUY |
.38 |
1.00 |
1.03 |
1.01 |
.99 |
1.02 |
1.00 |
4" Fiberglass
|
3# |
CLICK TO BUY |
.95 |
1.11 |
1.17 |
1.07 |
1.07 |
1.06 |
1.10
|
2" Mineral Wool |
8# |
CLICK TO BUY |
.39 |
.84 |
1.08 |
1.01 |
1.02 |
1.01 |
1.00 |
4" Mineral Wool |
4# |
CLICK TO BUY |
1.03 |
1.07 |
1.12 |
1.04 |
1.07 |
1.08 |
1.10 |
HOW TO READ THE TABLE ABOVE: For each material, frequencies ranging from 125hz (low frequency "bass") to 4000 (high frequency) are tested. Think of the number under each frequency as the percentage of sound absorbed by the insulation at that frequency (per ASTM C 432 test). For example, at 500hz, 1" Fiberglass Insulation will absorb 68% of the sound waves while the other 32% will be reflected back. Numbers highlighted in Red are the best for that frequency (closest to 1.00 or higher). The NRC (Noise Reduction Co-Efficient) is the arithmetic average of the sound absorption co-efficients at frequencies of 250, 500, 1000, and 2000. A NRC of 1.00 or above is preferred.
SUMMARY OF TABLE: From looking at the Noise Co-Efficients for each individual product, you first have to decide what type of application you have. If you are looking to dampen bass noise, you will want to use products that have high Co-Efficients in the lower frequencies (125 to 500). Your products of choice would be 4" Roxul Mineralwool or double layer 2" Fiberglass (4" total). 2" Fiberglass with 6# density is also a popular insulation board for bass traps in smaller rooms where space is tight.
If you are looking to reduce noise such as high frequencies or vocals (neighbors voices) you would be interested in products with high co-efficients in mid-range to high range frequencies (1,000 to 2,000). The least expensive product that fits this application is the very popular 2" Fiberglass 3# density (Owens Corning 703 Board).
HOW TO COVER PANELS WITH FABRIC: We simply sell the acoustic insulation panels without any fabric. Fabric should be stretched over the front of the panel and frame and fastened in the back with staples/glue. Frames can be made out of wood or plastic. We have had a great reception to the 2" thick Fiberglass panels with 6# Density. These panels do not need a frame and the fabric can simply be stapled to the back of the fiberglass board.
When choosing material for acoustic panels, a porous fabric is preferred to allow the sound waves through it so they can be absorbed by the insulation behind it. If the material is too thick and non-porous, the insulation will not be allowed to do its job, because the material will simply reflect it off the panel. We recommend the blow test. Take the fabric you want to purchase and blow through it, and see if your hand on the other side can feel your breath. Professional Acoustic Panel manufacturers usually work with Guilford of Maine fabrics. Although these fabrics are more expensive, they offer the highest acoustical transparency, Class A Fire Ratings, and the best textures and colors. We offer both Guilford of Maine Anchorage and FR701 fabrics online.
CLICK HERE FOR DIY BASS TRAP PANEL GUIDE
CLICK HERE FOR DIY ACOUSTIC WALL PANEL GUIDE
MASS LOADED VINYL
Mass Loaded Vinyl (aka MLV) is the sound proofing industry's replacement for lead sheeting. Lead sheet panels were at one time the best soundproofing material since it allowed no noise through it. Lead sheet panels as we all know is considered to be toxic material that we do not want to add to our studio, house, work space, etc.
The basic mass loaded vinyl product is manufactured through a mixing process of minerals and sand crystals. This combination gives it a set of characteristics similar to those found in the original lead sheets but without the potentially dangerous side effects.
The purpose of mass loaded vinyl is exactly as it sounds. It is used to add additional mass to an area or space, thus making it more difficult for sound to pass through walls and ceilings. It’s a popular soundproofing agent, especially when it comes to soundproofing personal spaces such as homes, music studios, home theater rooms, etc.
The introduction of mass loade vinyl products to the soundproofing industry had astounding results. It was not only a safe alternative to lead but was easier to use and apply. The sections are usually attached to the studs or joists of the area in question and then the seams around the edges are covered in acoustical caulk. After the caulk is applied the seams are taped over, ensuring that the seals are completed and that no sound will pass through.
Since mass loaded vinyl is great at blocking sound from penetrating a wall, ceiling, or floor, there may be an echo problem in some applications. This echo sound may be the direct result of the mass loaded vinyl reflecting the sound back into the room. However, there is an easy solution to this problem. A layer of fiberglass insulation applied on top of the mass loaded vinyl will help absorb the extra noise and not allow this echoing sound.