We have now over 135 rooms that we have built and measured. We measure everything from room size and volume to the vibration signatures of the room walls. In this data base, I have taken the data and broken it down into three categories. Each category is based upon an audio only usage. It as audio usage that involves an average sound pressure level of 85 dB SPL. The source can be speakers, instruments, or voice.
The first group of room sizes and volumes, the red group, is room sizes that produce so many low, middle, and high frequency energy issues, that large amounts of absorption treatments are required. There is not enough space for diffusion in terms of surface area or distance for wave lengths to fully form. It is the room sizes that are below 2,000 cu. ft. in total volume. The large amounts of treatment surface area, especially in the lower frequencies, will take up so much space that you might not be able to work in it. Forget about working around the room modal issues, there might not be a place to even sit.
It is usually best if your room size falls into this category to try and find another room size. The second group (yellow) of room sizes is from 2,000 – 4,000 cu. ft. This group of room sizes and volumes has the necessary space to allow for enough low, middle, and high frequency absorption along with enough space for diffusion. You have the space to place the appropriate low frequency absorption technologies and enough distance for diffusion to work. You will still have issues, especially in the low end but they can be predicted and managed.
The third group (green) is greater than 4,000 cu. ft. It is an ideal grouping of width, height, and length to allow for almost any usage. These rooms have enough distance to allow for appropriate management of all reflection time signatures unwanted modal pressures, along with enough distances to allow for diffusion to do its job correctly and allow for all diffused wave forms to fully form. Sam Small’s room fell into the red zone. Along with the small size and volume, Sam had dimensions that were coincidental (same in dimension) which means that unwanted low frequency issues are even more pronounced.
Small Room, Big Results
Sam’s room proves that you can achieve equal representation of all frequencies if you are willing to give up large amounts of surface area using diaphragmatic absorption. Diaphragmatic absorption that was custom designed and built by Sam to achieve high rates of absorption. If your room size and volume falls into the red zone, and you can not find another room size for whatever the reason there is a solution. You must be prepared to give up large amounts of space, have a budget that will be large enough to produce the required treatment technologies and spend many hours in the tuning process.
As you can see by the photos and video, you can place product in either a horizontal or vertical position. Think of your room as a glass of water. You have too much water ” low frequency” in your room or glass. We have to lower the water level in the glass, so that we can hear more clearly. We lower the water level by dropping sponges or absorbers into our room or glass. We need to first decide on the correct number of sponges and then position them in the areas where they will absorb the most.
ACDA-10 Activated Carbon
The ACDA-10 is our flagship, activated carbon, broadband, diaphragmatic absorber with low frequency absorption from 30 Hz. – 200 Hz. The face of the unit can be used to support one of our foam absorber thicknesses or one of our mini-diffusors in our MDP line. Units are designed with rigid side and rear walls and a dual wall, front panel construction that increases diaphragmatic action. The inside of each unit contains our activated carbon filters which increase the unit’s Q value through acoustical compliance enhancement. This activated carbon filter process is unique to low frequency absorbers and is patent pending. Solid wood and paint finishes are available. Each unit measures 60″ tall, 30″ wide, and 16″ deep. Each ACDA-10 unit weighs 225 pounds.
All rooms need low frequency energy control, unless you are fortunate enough to have a room that measures at least 30′ in one of it’s dimensions. The ACDA-10 is designed to be a broadband, linear, absorber targeting the 30 Hz. – 200 Hz. range. It is even effective at higher frequencies. With the ACDA-10 unit, you can also control unwanted middle and high frequency reflections through the application of one of our foam thicknesses, mini-diffusors, or a combination of both. You can now have broadband, linear, absorption from 30 Hz.- 6,500 Hz.
About Sam Small
Sam was born in Portsmouth on the south coast of England. Music thrilled him from the age of three. Pop music and rock music, mainly. Later on he got a guitar and discovered he could put chords, a melody and words into what is called a song. Several decades later he and his wife moved (permanently) to Austin Texas. He now runs a small studio in that great music town.
His influences go back to the beginning of time. Buddy Holly, The Everly Brothers, Bob Dylan, Joni Mitchell, James Taylor. Classic singer/songwriters still inspire.