When a musician decides to turn a room into a recording studio, she will encounter a lot of contradicting and confusing information. What is the best way to treat a room and turn it into a recording studio? Auralex has stepped up and combined two of its successful sound absorbing foam products to help a musician and a DIY acoustic foam design enthusiast. With the help of Auralex, the musician will be able to quickly and effortlessly sound treat any room. She will be able to significantly improve the quality of the recorded sound.
We will review Auralex Project 2 Roominator Kit sound absorbing foam (available at Walmart) in order to support that DIY recording studio enthusiast. She will be able to set up her recording studio with minimal cost, best possible materials, with no outside help of expensive “experts”. We will talk about optimal placement and orientation of the panels that you will find in the kit. Additional optional upgrades will be discussed. We will base our suggestions on the sound simulations that we showed in other posts on this site.
Contents OF Auralex Project 2 Roominator Sound Absorbing Foam Kit
The Auralex Roominator Kit contains Auralex 24 Studiofoam Wedge Panels with dimensions 2′ (H) x 2′ (W) of 2″ thickness. You can attach these to walls and the ceiling. In addition, the kit contains 8 pieces of Auralex LENRD Bass Traps. These are panels that fit in the corners of the room. You will also find 144 EZ-Stick Pro Adhesives for easy install. Due to the lightness of the Studiofoam sound absorbing foam you will find installation of the kit effortless.
The Regular Wedge Panels, Their Absorption And Diffusion
The surface shape of the Wedge Panels is one of what we termed “regular wedge” in this review post: Auralex Studiofoam Wedge Panels Soundproofing Foam Panels Review. We found these regular wedge panels to absorb sufficiently well for mid to high frequencies above 500 Hz. For adequate absorption at lower frequencies, between 100 Hz and 500 Hz, which are also important, we found that the “regular wedge” type foam such as Auralex Studiofoam Wedge, included in Project 2 Roominator Kit, is best suitable, absorption-wise, for angles of incidence around 30 degree to 45 degree. These are the mid-range angles of incidence.
What determines the angle of incidence? One must approximately figure where the most common location of the sound source will be. Then, draw a straight line from the source to the position at the wall. At that position of the wall, one draws a normal line, which is perpendicular to the wall at that point. The angle of incidence is then defined as the angle between the line of incoming wave, and the normal line. Typically, the incidence will be “normal” at the position on the wall which is closest to the sound source. As one goes farther away from that position, the angle of incidence increases. The largest angles of incidence will be at the very far end of the side wall in the room.
Further Improving Absorption And Diffusion
The upshot of this is that, the “regular wedge” type panels such as Auralex Studiofoam Wedge panels included in the Roominator Kit will still work in all placements in the room, but for better absorption and better diffusion, you may want to consider supplementing them for the placement on the wall closest to the sound source with the Auralex Pyramid Foam reviewed here: Sound Deadening Foam Panels With Diffusion: Review Of Auralex Acoustic Pyramid Foam, or the Auralex DST-type foams reviewed here: Best Acoustic Foam: Acoustic Wedge Foam Auralex DST 112, DST 114 Review. Likewise, for placement in the far-end sides of the room (angle of incidence 60 degrees and over) you will improve absorption by substituting with the Auralex DST-type foams.
What about the orientation of the Auralex Wedge sound absorbing foam included in this Kit? The Wedge foam comes in 2 ft by 2 ft square panels. Thus, you can orient it in any direction. We recommend orienting it such that the ridge of the wedges are perpendicular to the direction from the sound source. That way, one side of the wedge will face in the direction of the sound source, which will maximize the transmission of sound into the foam, and thus, the absorption will be maximal. We have discussed this in the post on placement of sound absorbing foam in the recording studio here: Acoustic Sound Foam Placement In Recording Studio. Part 2, Oblique Incidence.
Bottom line, by heeding the advice in this section, the sound impinging on the wedge panels will be maximally absorbed. The remaining sound that will still be reflected back into the room will be diffused. This means that the sound will go back into the room in random directions. This will allow the sound to be absorbed in other wedge panels mounted on other walls in the room, or on the ceiling. In addition, the sound that impinges onto the corners of the room will be absorbed by the second component of the Auralex Project 2 Roominator Kit, the LENRD Bass Traps.
LENRD Bass Traps, Their Role In Sound Absorption And Diffusion, And Placement
LENRD Bass Traps are the second important component of Auralex Roominator Kit. LENRDs absorb and diffuse the sound that hits the corners of the room. Why are LENRDs so important? And what is their best placement?
Sound Absorption Of LENRD Bass Traps
Table below shows the Noise Reduction Coefficient, NRC, and Sound Absorption Coefficients for a variety of relevant frequencies from 100 Hz on.
As you can see, the sound absorption coefficients for LENRD are over 1.00 for frequencies between 100 Hz and 5000 Hz. This indicates full absorption at these frequencies. Surely, this is due to LENRD high thickness. You should place LENRD foams in corners of the recording studio.There, LENRDs won’t take up much of the useful space.
The basic physics of mirrors explains what happens when a sound impinges on a corner of the room where the three walls that are coming together are at a 90 degree angles relative to one another. The sound will bounce once off of each wall. Due to the law of reflection, the sound will bounce back exactly in the opposite direction from where it came from.
Such perfect back reflections are detrimental for the room acoustics. Back reflections enable creation of back-and-forth reflections from one corner of the room to another. This then builds up standing waves at certain discrete frequencies. At these discrete frequencies, the sound will be disproportionately amplified. The sound recording will suffer due to unusual amplification at these frequencies.
So it is best to avoid the buildup of such standing waves bouncing off the corners of the room. Absorbing as much sound as possible in the corners of the room will do the trick. This is the role of Auralex LENRD Bass Traps, included in the kit.
Placement Of LENRD Bass Traps
Based on this, the best positioning of the LENRD Bass Traps is in the corners of the room that are closest to the sound source. The reason for positioning them as close as possible to the sound source is so that the sound is absorbed in them when it is most intense. The sound is most intense closest to the source, before it reflects off of any wall.
Assuming good, thick, sound absorbing carpeting in the room, it would then be advisable to place LENRD Bass Traps in the upper corners of the room, the corners closest to the sound source. If you have any Bass Traps left over, installing these in the bottom corners of the room would make sense also.
What about diffusion of the reflected sound that reflects off the LENRDs? Well, since the absorption of the sound anywhere between 100 Hz and 4,000 Hz is so complete, there is hardly any reflected sound. Thus, the amount of diffusion of that sound is not very important.
Material’s Fire Retardancy And Durability
The material that both Wedges and LENRD foams are made of are open-cell polyurethane foams. They are light, yet absorb mid to high frequencies above 500 Hz practically 100%. For frequencies below 500 Hz, the proper positioning of Wedges as described above will allow for maximal absorption there too. The LENRD foams are much thicker than the Wedges. LENRD foam will have much better absorption at lower frequencies 100 Hz – 500 Hz. Practically all relevant sound impinging on them will be absorbed.
The polyurethane foams are Class-A rated as far as fire retardancy. Before installation, you should still check with the local laws as far as restrictions on installation.
Appearance, Colors Available
Auralex Project 2 Roominator Kit comes in Purple, Burgundy, and Charcoal color. If you decide to combine Roominator Kit components with Auralex Pyramid Panels or Auralex DST Panels as suggested above, the color combinations will match.
See Auralex Project 2 Roominator Kit at Walmart.com.
Note: It has come to our attention that, recently, Auralex Project 2 Roominator Kit has been out of stock. We recommend looking into the Auralex Roominator D36-DST here at Walmart instead.