Acoustics Glossary

The ZR Acoustics® design paradigm is a revolutionary Quantum Technology. As all innovative technologies require new language and phrases to define and quantify their function and character, DHDI has created a brief glossary of terms to help clarify and understand ZR Acoustics® and Quantum Acoustics™. The glossary is divided into two sections for easy reference.

ZR Acoustics® Terminology | Quantum Acoustics™

Traditional Acoustic Terminology | Classical Mechanics

ZR Acoustics® Terminology | Quantum Acoustics™

Dimensionality

Imaging of sound and acoustics which is perceived as three dimensional or spherical, possessing obvious and clear elements of depth, width and height.

Extreme Acoustic Resolution

A high degree of resolution utilized in acoustical design and the design of quantum acoustical devices. Measured in NPS/ft.², Extreme Acoustic Resolution is regarded as 0.5 NPS/ft.² or greater, a factor of 50 times beyond that of traditional acoustic resolution. (see references below)

Reference:

Traditional Acoustic Resolution = 0.01 NPS/ft.²

Extreme Acoustic Resolution > 0.5 NPS/ft.²

Quantum Acoustics™ Resolution > 140.00 NPS/ft.² | (ZR Acoustics®)

Life-Like Imaging | Spherical Imaging

The acoustical equivalent of photo-realistic.
Acoustical imaging so Life-Like that listeners often describe it as “as realistic than the real thing”.
Imaging as if in a sphere, like the real world. The sound of life on the planet.
A recording of a musical performance that the audience thinks it “sounds exactly like or better than the actual live performance.”
The goal of an acoustical environment: to create an environment which is so “Life-Like” it has no flaws and is free of interference from classic acoustic issues such as resonances, standing waves, comb filtering or variable frequency response with volume.
A recording with sound imaging that sounds so natural and clear that it feels completely realistic.

NPS/ft.²

Non-Parallel Surfaces per square foot: the number of surfaces which are not parallel to another wall or surface in one square foot of space. NPS/ft.²was created as a unit of measure to accurately quantify acoustic resolution, necessitated by a significant differential in resolution between Quantum Acoustics™ and traditional acoustics.

Acoustical resolution is directly related to acoustical performance and it’s defining characteristics: Imaging, Definition, Clarity and Intelligibility. Higher resolution values result in higher acoustical performance.

Classical mechanics and traditional acoustics require the angle of the non-parallel surfaces to be a minimum of 7 degrees to be effective. Quantum Acoustics™ utilizes a wider spectrum of vectors, angles and resolution to achieve quantum behavior in the acoustical realm.

Phase Coherency

A reference of the time difference between direct and reflected sound. Phase Coherency, or 100% Phase Coherency exists when the difference between the two signals is zero. In acoustics and audio, it is typically measured in percent (%), samples (DSP), or time (seconds, milliseconds).

In human binaural hearing, Phase Coherency plays a significant role in measuring speed and distance. It is also an essential component of echo-location. The term “imaging” is based on the human ear’s ability to perceive depth, width and height by comparing time differentials between various audio signals. High Phase Coherency is considered a critical element of Life-Like Imaging, Clarity and Dimensionality.

Quantization

In acoustics, the conversion of sound energy in air molecules from wave behavior to particle behavior. This conversion creates quantum behavior in air molecules, preventing the existence of sound energy and therefore sound waves.

Sweet Spot

A colloquialism referring to the best sounding spot in a recording studio, theatre or performance space when used to describe acoustics. “Sweet Spot” is the location in a room where the 4 critical elements of acoustics are in peak alignment: Imaging, Definition, Clarity and Intelligibility. Traditionally, it is a small area approximately 1 cubic foot or less located at the mix position of a recording studio. In a theatre or performing space it is on the orchestra level, on the center line and roughly 1/3 to 1/2 way back from the proscenium arch.

Wall-to-Wall Sweet Spot

A colloquialism referring to a sweet spot the size of an entire room: from wall to wall. While traditionally only 1 cubic foot, the phrase “Wall-to-Wall Sweet Spot” is used in reference to spaces designed using the ZR Acoustics® design paradigm with unusually large sweet spots ranging from 100 cubic feet to the entire air volume of a room; hence the term “Wall-to-Wall”.

ZR Acoustics®

ZR Acoustics® is an acronym for Zero Reflection Acoustics.
ZR Acoustics® is a acoustical design paradigm for achieving Quantum Acoustics™.

Quantum Physics

Dr. Shohini Ghose discusses Quantum Physics on TedX.

Traditional Acoustic Terminology | Classical Mechanics

Absorption

Acoustic absorption refers to the process by which a material, structure, or object takes in sound energy when sound waves are encountered, as opposed to reflecting the energy. Part of the absorbed energy is transformed into heat and part is transmitted through the absorbing body.

Comb Filtering

Comb filtering is a delayed version of a signal overlapping the original, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly spaced notches, giving the appearance of a comb.

Diffusion

Diffusion, in acoustics and architectural engineering, is the efficacy by which sound energy is spread evenly in a given environment. Virtually all traditionally designed spaces are non-diffuse. Spaces which are highly non-diffuse are ones where the acoustic absorption is unevenly distributed around the space.

The diffusiveness of a sound field can be measured by taking reverberation time measurements at a large number of points in the room, then taking the standard deviation on these decay times. Alternately, the spatial distribution of the sound can be examined.

Small sound spaces generally have very poor diffusion characteristics at low frequencies due to room modes.

Reflections

Reflections are the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. Mirrors exhibit specular reflection. In acoustics, reflection causes echoes and is used in sonar.

Resonant Frequency

The term resonance (from Latin resonantia, ‘echo’, from resonare, ‘resound’) originates from the field of acoustics, particularly observed in musical instruments, e.g., when strings started to vibrate and to produce sound without direct excitation by the player.

Frequencies at which the response amplitude is a relative maximum are known as the system’s resonant frequencies or resonance frequencies. At resonant frequencies, small periodic driving forces have the ability to produce large amplitude oscillations, due to the storage of vibrational energy.

Sabine Coefficient

Attenuation measured in Sabin Units. I.E. a ratio of how much sound within the human threshold of hearing is attenuated in relation to a Sabin rating of one square foot of material.

Sabine Unit

The sabin is defined as a unit of sound absorption. Sabins can be calculated with either imperial or metric units. One square foot of 100% absorbing material has a value of one imperial Sabin. One square metre of 100% absorbing material has a value of one metric Sabin. The unit is named in honor of Wallace Clement Sabine.

Sabines are measured broadband. However, they do not compensate for the inherent nature of most acoustic materials to absorb sound energy to varying degrees at varying frequencies. I.E. 2″ inch of a certain material can have exactly 2x the sabine rating as 1″ of the same material, yet their absorption effects different frequencies of sound to different degrees of amplitude.

Standing Wave

In physics, a standing wave – also known as a stationary wave – is a wave in a medium in which each point on the axis of the wave has an associated constant amplitude. The locations at which the amplitude is minimum are called nodes, and the locations where the amplitude is maximum are called antinodes.

Standing waves were first discovered by Franz Melde, who coined the term “standing wave” (German: stehende Welle or Stehwelle) around 1860.^[1]^[2]^[3]^[4]

Standing waves are also observed in physical media such as strings and columns of air. Any waves traveling along the medium will reflect back when they reach the end.

ZR Acoustics® | Glossary of Terms

ZR Acoustics® | Glossary of Terms

ZR Acoustics® | Glossary of Terms