Listening Experience
Most individuals that want to build a room to record sound energy within have not done done much listening in actual rooms. They have spent time sitting near field in front of their monitors but they really do not know how a room sounds. Their listening framework consists of all of their experience through the tears, sorry years, of listening to many different speakers within many different rooms. Familiarity breeds comfort, even if some comfort is missing.
No Pain, No Gain
Engineers who receive recognition and fame may have earned that recognition and fame for a single hit or song. Their overall knowledge level about good room sound may not equal their recording skill set. Marketing creates hype with flash and sizzle that no engineer can keep up with in order to try and make a living in the business. If it is not good sound, they may not know and do not want to say. Unrealistic expectations combined with this marketing hype creates a need to go along with the status quo and not upset the apple cart, even if the majority of the apples are spoiled.
Many Variables
There are so many variables that must be considered, it is difficult to get a good consensus on what a good sounding room is. Room size, equipment, and the quality levels of musicians are critical. What materials do we use within the room to create the sounds at the microphone position we need for that particular instrument? Where do we locate the microphone, once we have designed the rooms for minimum resonances at the microphone position.
Peer Pressure
Marketing programs by large corporations create a following that then turns into peer pressure. This peer pressure turns into expectations and maybe these expectations are realized but mostly they are not. Claims that foam will resolve excessive low-frequency energy should be checked against absorption data for the specified material, thickness and mounting at the frequencies of concern. Select treatment for the room’s measured low-frequency problems.
Real Room Acoustics
A room designer must wade through all the noise to find the truth. He must deal with all of these human perceptions and myths and construct a room that has some basic consistencies to it. Room size should be assessed alongside the intended use, loudspeaker layout and required acoustic performance. We must start by understanding the room’s dimensions and constraints.
Size Does Matter
Room length, width, height and volume affect room resonances and the response at the listening position. Evaluate these dimensions together with loudspeaker and listener positions and the proposed treatment. Room length alone does not establish usable low-frequency performance.
Room Height
Room height affects floor-to-ceiling modes and reflection paths. Assess it together with room length and width, source and listener positions, and treatment. Select dimensions for the project’s acoustic objectives rather than applying a universal minimum height or a single golden ratio.
Wall Construction Techniques
Wall construction should be selected for the required sound isolation, structural needs and room use. Wood-frame, steel-stud and masonry designs can be considered; performance depends on the complete assembly, including connections, cavities, lining layers and flanking paths. A material label alone does not establish sound isolation or in-room sound quality.
Low Frequency Absorption
Low frequency absorption must have the necessary rates and levels of absorption to insure all low frequency resonances are under control. Proper low frequency management techniques must be employed at the proper room position to absorb the necessary magnitude of the resonance. Thin foam panels are not a substitute for selecting low-frequency treatment from appropriate absorption data. Performance depends on material, thickness, mounting and frequency; there is no universal 100 Hz cutoff for every porous absorber.
Middle and High Frequency Absorption
Middle and high frequency absorption technologies must also have the necessary rates and levels of absorption in order to maintain the musical integrity of the reflection we are controlling. We do not want to over absorb the reflection. We just want to minimize its strength to reduce its impact at the monitoring or listening position.
More Not Better
Most middle and high frequency technologies in the marketplace today over absorb energy to reach high absorption coefficients in order to sell more product. More is not necessarily better when dealing with reflections. We do not need to destroy energy through too much absorption in order to manage it.
No Compromise
Everything in life is a compromise. However, when one is concerned about and places a high value on sound quality within a room, there are areas that can not be compromised. Designers must stick to their beliefs and tell a client to choose another room if compromises for the chosen room look longer on a list than does the equipment. Sometimes, one must just say no.
