Bob Hodas
More small project studios and home studios are doing significant work in the commercial market. What are the primary acoustic challenges of these small rooms?

Dr. Peter D’Antonio
The goal of a project studio is to record and mix music, which will transfer to all listening environments. Unfortunately, the music that you hear in a project studio is distorted by interfering reflections from the room’s boundaries. We call this effect Acoustic Distortion. Your readers should appreciate that in a project studio you are listening to a distorted view of reality, like looking at the world with rose colored glasses. It’s startling when you remove them and appreciate the full spectrum of colors that are really there! Room reflections affect imaging (the detailed placement of sonic images across the soundstage), the low frequency response and the reflection density (what our ear and brain mechanism uses to determine spaciousness, envelopment, and ambiance). Thus the primary acoustic challenges of project studio design are to provide accurate imaging, uniform frequency response, and a uniformly diffuse and spacious listening environment.

Q
What kind of solutions to these problems do you suggest?

A
RPG®’s Acoustics Research Department has studied these rooms in significant detail and we have developed specific AcousticTools which address the three areas of imaging, low frequency response, and spaciousness. We call these Imaging Tools, Bass Tools, and Spatial Tools. To make application easy for Project Studio owners, these three ingredients have been packaged into Silver, Gold, and Platinum room packages for a wide variety of room sizes. These packages are sold internationally through Pro Audio Dealers and Catalogs. RPG® has trained these distributors to properly apply the products.

We offer two Imaging Tools. Low cost Class A ProFoam™ and a fabric upholstered Abflector™, both of which take advantage of RPG® variable depth air cavity (VDAC) technology. These Imaging Tools provide broad band attenuation of first order room reflections which corrupt imaging. They are applied at ear level on the side walls between the speakers and the listening position and on the front wall of the room between the speakers.

We offer two Bass Tools. The new low cost Melaflex ProCorner™ or RPG®’s proprietary membrane low frequency absorber, which has an absorption efficiency of 100% at 71 Hz, the modal frequency of most project studios with an 8' ceiling. Both Bass Tools mount in a corner and are stackable.

Finally, we also offer two Spatial Tools. The low cost ProFoam™ or RPG®’s patented 2D Skyline® diffusor. The Skyline is the only 2D diffusor available which is based on mathematical number theory for unprecedented diffusion and “cool” looks. It is mounted at ear height on the rear wall behind the listener.

Q
Do you see any correlation between small and large studio problems?

A
There are some parallels and some differences. With respect to speaker placement, most larger professional studios use flush mounted speakers and project studios primarily use mid or near field monitors. A speaker’s response in a project studio is significantly dependent on its location and the acoustical design, regardless of how flat its frequency response is in a reflection free environment. Manufacturers go to great lengths to obtain a flat anechoic response, only to have this response compromised by an acoustically poor room design or improper loudspeaker placement. Placement is so important that RPG has developed Room Optimizer™ software to determine the optimum location of the main speakers and subwoofers.

Because the distances between the mixing position and the room’s boundaries are small in a project studio, these rooms are more affected by strong specular reflections. In addition, modal frequencies are higher in smaller rooms. Thus more efficient absorbing Imaging Tools, properly tuned Bass Tools, and Spatial Tools are needed. AcousticTools for Project Studios address all of these issues in easy to use packages. In a matter of hours you can acoustically treat a project studio and create an improved listening environment.

Q
What common mistakes do you see made when people set up new small control rooms, and what advice would you give to avoid these initial mistakes?

A
For many years in studio design and broadcast design, the only good reflection was a “dead” reflection and the axiom “the deader the better” was the norm. I hope that over the last 13 years with tens of thousands of our diffusor systems installed in leading edge facilities worldwide, RPG® has made the case for a more balanced design using absorption, reflection, and diffusion. Despite this track record, the most common mistake is that project studios are often made too dead using mid to high frequency absorbing sculptured foam. By treating large areas with a mid to high frequency absorber, you accentuate the bass problems and create a very uncomfortable working environment.

Another important issue is that urethane foams can create a potential fire and safety hazard and do not meet ASTM Class A fire codes. The key here is to approach project studio design in a balanced manner, use Imaging, Bass, and Spatial tools to address all of the room’s problems.

Another mistake is to assume that by using near field monitors, acoustical design is no longer important. This couldn’t be farther from the truth, especially if we consider the significant reflections from the table top of a DAW or a console. With the growing use of subwoofers and the impending 5.1 multichannel music format, the room will not go away! Therefore, simple and effective approaches like AcousticTools for Project Studios will make even more sense in years to come.


SF NARAS Newsletter
November 23, 1996