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Good Room Sound Has Many Demands

By November 16, 2012No Comments

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. We all have heard how foam can stop excessive low frequency energy within our small rooms. Nothing could be further from the truth, but they say it anyway. Unfortunately, people literally buy into it.

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. There must be some givens in the room design equation that must be met and there is no compromise on these variables. We must start with room size.

Size Does Matter

There is a minimum room size we must have to start. It is a room size and volume that can deal with room resonances and not make things worse for recording or monitoring. There is a ratio of room sizes that lend themselves to good acoustics. One of the most important dimensions is room length. We must have at least 30′ in room length to have a room that will have a chance of measuring down into the 20 cycle range. There is no exception to this requirement.

Room Height

Room height is another no compromise situation. The parallel surfaces between the floor and the ceiling are big contributors to low frequency build up and a whole host of middle and high frequency issues. There must be adequate height in our golden ratio of height,width, and length, to be conducive to minimizing those issues. We must have a minimum height of 12′ to accomplish at a minimum these acoustical objectives. There is no exception to this requirement.

Wall Construction Techniques

The wall construction methodology must use block or brick. Wood frame is not acceptable to producing real quality sound. Frame does not produce any isolation nor does it produce any real quality sound. Frame construction moves too much. Sound pressure energy can cause frame construction to move or vibrate just like a speaker does. The wall goes diaphragmatic and begins producing sound of its own. The vibrational plates of frame construction adds to the vibrational levels within the room and will contribute to the room’s sonic signature. Walk into a wood framed room. Now, walk into a brick room.It is not difficult to hear the difference. Lower structural vibrations are always conducive to a better sounding room.

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. Foam will not work and do not believe the marketing slogans. Foam is only applicable above 100 Hz. no matter what the manufacture claims its low frequency absorption capacities are.

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.


I am a structural engineer as well as a master furniture maker. I design cabinets for low frequency, activated carbon absorbers. Connect with me on Google+

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