Sound is conveyed through waves in the air. Waves that exist between a pair of surfaces can create standing wave resonances whenever the distance between the surfaces is any even multiple of one-half of the wavelength. At resonant frequencies (tones), the sound is louder and decays much more slowly than at non-resonant frequencies, causing uneven tonal quality and interference with clarity. Resonant frequencies occur mainly in the bass range, due to the relationship between the wavelengths of low-frequency sounds and the typical sizes of listening rooms.

This wave is in a standing wave resonance since it's wavelength equals the
distance between the pair of surfaces.

Every room has its associated resonant frequencies. Rooms built using preferred dimensions ratios have potentially more even distributions of these resonant frequencies. Room built with angles walls or ceilings have more complicated resonant modes than typical rectangular rooms and the resonances can be potentially less severe. But, no matter what the size or shape of the room, resonant frequencies can be controlled through the use of bass traps.

"Bass" frequencies occupy all the notes on the left half of the keyboard (Everything below middle C). Since this is such a large portion of the musical spectrum, and because every room has potential resonant frequency problems in this bass range, it is imperative that the low frequencies be the first issue to address in improving any room's acoustics. Of course, each specific room's geometry, setup, and application dictate how to best optimize the bass performance. However, there are some general enhancements that can be made using ASC TubeTraps that are sure to offer improvement in any room.

There are certain paths for sound that produce a repeating loop. Every time the wavefront passes the listener it is heard as the sound is intended, but with a twist. Just as when you "click" the individual prongs on a comb in quick succession, the quickly repeating sound of the wavefront continuously passing the listener produces a distinctive "zinging" tone. This is known as flutter echo and is due to our brain's desire to interpret air pressure fluctuations at some frequency as a particular tone. For this is exactly what is occurring as the wavefront continuously passes your ear at some rapid rate.

The flutter paths are most commonly located along lines between parallel surfaces. Speakers located between parallel surfaces are constantly sending sonic wavefronts into the repeating loops of these flutter paths.

Placing ASC TubeTraps, SoundPlanks, or SoundPanels at the reflection points for these flutter paths breaks up the flutter. This removes the tonal discoloration caused by the "zinging" sounds our brain interprets from the repeating wavefronts it encounters.

As seen in sections 2 and 3, controlling room reflections is fundamental to creating accurate sound reproduction in any room. In addition to utilizing precisely selected panels addressing comb filter and flutter problems, it is also generally desired to include the proper combination of absorption and diffusion to control sounds reflected throughout the room. The desired balance of absorption and diffusion is obtained through selection of appropriate absorptive material and proper placement to create diffractive diffusion and/or multiple time-delayed specular diffusion.

The proper placement and selection of panels to attain the desired reflection control is determined on a case-by-case basis due to the large number of variables involved.

Sound produced within any enclosed space will continue to exist in that space for some amount of time after it is created, decaying away until it is inaudible. If this decay time, known as the room's reverberation time, is too long, sounds will linger within the space and begin to overlap with new sounds being made, creating an unintelligible caucauphony.

Long reverberation time = Poor Intelligibility
 

Short reverberation time = Good Intelligibility

A sufficient amount of acoustic absorption is required at all audible frequencies of sound in order to keep the reverberation time in a room short enough to have good intelligibility. The measurement of the reverberation time in a room is often referred to as RT60. The desired RT60 at an frequency varies from room to room. All ASC acoustic treatments alter the RT60 of a room to some degree. Acoustic treatment is developed with desired RT60 levels in mind.