The Curve Combination Guide:
Garage-Size Recording Studios

Curve System components may be used in combination to solve most of the acoustic issues found in home theater and music listening room environments.

After a hundred years of acoustical science, we know that smooth reverberation times, a relatively flat frequency response, widely-spaced room modes, and a lack of flutter echos are key elements of the best-sounding rooms. The way to achieve those goals has always been the proper balance of diffusion, absorption, and low frequency control. While room size and dimension ratios place a limit on what can ultimately be achieved, here are a few tips to improve your recording and mixing experience.

A few points to consider:

• The larger the room volume, the lower the fundamental frequency of the space;

• Rooms with less than 1500 cubic feet of volume are less desirable, due to room-mode buildup above 200Hz and limited low frequency response;

• Proper ratios of height to width to length are necessary in spreading room mode instances. Optimum room ration resources can be found online at a number of "room mode calculator" links.

• And most importantly, all rooms are different, and sound preferences vary widely from person to person.

This guide suggests diffusor and absorber placements for a recording studio built into a space the size of a standard 2-car garage (about 24' x 22'), a widely available type of structure. You may choose a different way to set up your studio for the results you want - remember that Curve System components are modular and moveable, so you can experiment with different arrangements until you have the proper acoustic balance.

A "proper balance" doesn't mean a 50/50 split between diffusion and absorption - it means the right combination to achieve the most balanced sound. Rooms with too-long reverberation times may need more absorption than diffusion; conversely, too-short reverberation times may need more diffusion. The important goal is finding the right combinations for your space.

The placement of Curve components is made easier by considering each unit's function:

• The three Diffusor sizes are meant to spread the sound energy of flat-wall reflections and absorb low frequencies (by diaphragmatic and limp-mass membrane absorption), and mixing their order, for example a Medium next to a Small, avoids comb-filter artifacts. Changing the components' orientation - vertical or horizontal (or even diagonal) - will diffuse sound in different planes, for example a vertical orientation diffuses in the horizontal plane;

• Absorbers are meant to be used in conjunction with Diffusors to absorb sound in the 200-20kHz range, and its similar form allows combining it with Diffusors wherever needed acoustically without changing the visual design;

• The Corner Trap is designed to work in any corner - walls and floors or ceilings - where three surfaces (planes) meet. The Corner Trap can also be used where two surfaces meet, such as ceiling and wall, keeping in mind that all room modes are present in three-plane corners, while only perpendicular modes are present at two-plane junctions;

• The Mass-Loaded-Vinyl membrane built into each Diffusor also helps control low frequencies, and where they are placed is important for both diffusion and low-frequency control.

Control Room Component Placement

This control room has about 1700 cubic feet of volume with 12 Curve components. There are no units shown on the ceiling, definitely an option to consider (more later). Three Corner Traps are located at the left-front floor nearest the low-frequency sources and at the two rear wall-ceiling corners. One Large Diffusor is centered on the left-side wall to help control bass in the longest room dimension and to add vertical diffusion, and the Medium Diffusor on the right-side wall diffuses horizontally as well as helping to control low frequencies. Two Absorbers and a Medium Diffusor on the back wall help diffuse and absorb rear reflections.

On the front wall, we've placed two Absorbers horizontally and two Small Diffusors vertically to help break up and absorb reflections from the large sheet of glass.

 

 

 

 

 

On the back wall, the Medium Diffusor and two Absorbers are positioned approximately centered at the level of the seated sound mixer's ears. The right-side wall (referenced to the mixing position) Medium Diffusor and left-side wall Large Diffusor are likewise approximately the rear-wall reflections, and placement in the three-axis corners where all room modes are present means the Traps are helping control all room modes (this is also true for the left-front Corner Trap, as all room modes are present there as well).

The right-side Medium Diffusor also serves to break up some of the small angled window's reflections. Because all Curve Diffusors have Mass-Loaded Vinyl membrane absorbers built-in (and all Diffusors function as diaphragmatic mid-low-frequency absorbers), their placement is also important to low frequency control. The two window-side vertical Small Diffusors work in the room's second-largest dimension, along with the Medium Diffusor on the rear wall, to control low-frequency energy on that axis.

Studio Component Placement

In the studio, note the two Large Diffusors placed horizontally and vertically in the approximate centers of the two adjacent walls to diffuse sound in the vertical and horizontal planes. This also places large membrane absorbers (built into the Diffusors) on the surfaces that will help control low frequencies in the room's two prime axial dimensions. The two vertical Absorbers near the drums help control reflections off the back and side walls, and the two semi-stacked Corner Traps help control low frequencies and diffuse the drums. The studio has about 2600 cubic feet of volume with 16 Curve units.

Like the control room, we've placed two Absorbers end-to-end horizontally and two Small Diffusors vertically to break up and absorb reflections from the large sheet glass. A good general rule is to use most of the Diffusors and Absorbers on the walls for horizontal and vertical diffusion and absorption (we hear more left-right than up-down).

 

 

 

 

 

On the studio back wall, the Medium Diffusor helps diffuse sound reflections between the window wall and the back wall, as well as helping to control low-frequency energy on that axis. The horizontal Absorber next to the Large Diffusor helps absorb the opposite angled wall's reflections and generally adds broadband absorption to the room (and near the drums).

There are five Corner Traps in this space to control the large amount of low-frequency energy generated by the drums, bass guitar amp, guitar amps, and piano. In each Corner Trap the thick recycled cotton absorption material, in addition to the Diffusor's built-in MLV membrane and diaphragmatic absorption capabilities, allow the Traps to control a great deal of bass content in the room.

Diffusors on the ceilings can help with some vertical modes and flutter echos between floor and ceiling (though carpeting will dampen some very-high-frequency flutter echos).

The Diffusors shown are optional but highly recommended for diffusing the large ceiling surface areas, as well as adding needed low-frequency control in the vertical axis (again, due to the built-in MLV membranes). In the control room there are two Medium Diffusors centered end-to-end, left-to-right, approximately above the mixing console chairs.

In the studio, two Medium Diffusors and two Small Diffusors are set at 45-degree opposing angles - this serves to further diffuse sound in two room dimensions and also avoids comb filtering (the result of multiple one-size Diffusors in the same orientation).

The fabrics covering the Curve System components are available in five stock colors, as well as custom colors and wood veneer options.

If you would like more assistance in choosing Curve units for your rooms, please contact one of our acoustics professionals at Acoustic Geometry. Email: info@acousticgeometry.com; Phone: 1-888-227-6645.

 

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