CLIO 11 - Audiomatica · CLIO 11 Directivity and 3D Balloons News and Updates 17-20 Oct. 2013 135th...
Transcript of CLIO 11 - Audiomatica · CLIO 11 Directivity and 3D Balloons News and Updates 17-20 Oct. 2013 135th...
CLIO 11
Directivity and 3D BalloonsNews and Updates
17-20 Oct. 2013135th AES ConventionNew York, NY, USA
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Summary
● New redesigned Directivity & 3D Balloons menu● Overlap between directivity and time-frequency
analysis menus has been removed● Menu is completely dedicated to directivity analysis
– Directivity: Single polar scan-lines– 3D Balloons: Sets of 3D polar measurements
● Powerful 3D interpolation and data management ● Flexible export features towards CLF and EASE
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New CLIO 11 Menu Structure
Waterfall, Directivity & 3D
CLIO 11
Wavelet Analysis
CLIO 10
Directivity & 3D Balloons
Time-Frequency Analysis
● Directivity analysis requires as input a set of files (polar measurements)
● Time-Frequency analysis process a single impulse response
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2D Directivity Analysis
● Single plane polar response analysis (2D)
Root file set name
Start, stop and referenceangles
Reference to on axis value
Frequency smoothing
Root file set name
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3D Balloon Analysis
on-axisdirection
DUT response should besampled over the whole space surrounding the speaker
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Sampling Approaches
● There are several ways to sample the surface of a sphere:● Equiangular sampling● Equal area sampling● Spiral sampling● Random● [...]
● AES standard for loudspeaker directivity measurements recommends the Equiangular Sampling with 5 degrees resolution
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AES56-2008
● AES56-2008: AES standard on acoustics - Sound source modeling - Loudspeaker polar radiation measurements
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Spherical Coordinates
A point in the sphericalcoordinate systemis referenced by threeparameters:
r – sphere radiusθ – polar angleφ – azimuth angle
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Naming Scheme
● CLIO has a naming convention to handle spherical coordinates data:
<filename> φ*100 θ*100.mls
● The file name indicates the direction on the spherical surface
● Angles can be either positive and negative, CLIO 11 will take care of the conversion to positive spherical coordinates
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Why Equiangular Scan-Linesare called Polars?
If we think at the Earth oriented as such the on-axis directionof emission of the loudspeakeris the north pole...
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Why Equiangular Scan-Linesare called Polars?
The horizontal planescan-line runs throughthe poles...
So it is a polar...
If we use the same naming ofEarth scienceswe should call itmeridian
The horizontal (half) polarφ=0 scan-line is the Greenwich meridian
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Equiangular Sampling Single Polar
The horizontal polarφ=0 scan-line
θ angle is rangingfrom 0 (front) to180 (back) with 5 degreeresolution
φ=0; θ=0
φ=0; θ=180
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Equiangular Sampling Scan-Lines
Here is an exampleof a set of scan-linesfor a φ resolutionof 30 degrees
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CLIO 11 Balloon Representation
● CLIO 11 uses as internal reference resolution an equiangular 5 degree resolution● 2664 points● Standard as per AES56 and simulation softwares
● CLIO 11 stores data in third octave bands● From 20 Hz to 20 kHz
● Only magnitude data is shown in form of “inflated” directivity balloons● Balloon radius is proportional to level according to a
given range
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CLIO 11 Input Panel Options
Balloon Data Setvisual help:
Missing data
Balloon Data Setvisual help:
Unused data
Available data
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CLIO 11 Sampling Options
● Equiangular Sampling● Sphere should be
sampled over a set of half-polars lines
● Resolution of sampling in angles θ and φ is fixed
● Natural extension of single plane scanning
● Free● Minimum 1 point,
maximum 9999 points● At least the on-axis
point should be sampled
● A set of random or custom arranged points can be supplied
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Interpolation Modes
● CLIO 11 internal balloon representation needs full sphere data at 5 degree resolution
● In case of reduced data sets available ● Mirroring data by symmetry● Interpolation of missing data
● CLIO 11 has two interpolation options:● Bilinear interpolation● Inverse Distance Weighting interpolation
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Interpolation Modes
Equiangular Free
Bilinear Y
IDW Y Y
Symmetry Options Y
● In case of Free sampling symmetry options and bilinear interpolation are not available:
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Interpolation - Bilinear
● The missing data is linearly interpolated in two steps
1) Data is interpolated alongthe polar scan-lines (θ angles)
2) Data is interpolatedalong the azimuth(φ angles)
1)
2)
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Interpolation - IDW
● J.Panzer, D.Ponteggia, “Inverse Distance Weighting for Extrapolating Balloon-Directivity-Plots”, presented at 131st AES Convention 2011, New York
● Robust method to extrapolate data from reduced data sets
● No assumptions on data sampling and number of samples
● Minimum 1 sample data
● Smooth balloon surface by algorithm definition
● Weighting factor “u” can be adjusted (typical values 2<u<3)
Interpolated data
Known data points
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3D Import Example – H Symmetry
● Balloon of a H symmetrical box
● Interpolation madeusing bilinear mode
● Measurements madeat 5 degree resolution
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Data Export
Export Formats
Tabular formats asEASE .xhn ASCII or CLF v2 .tab
Set of impulse responses to be imported by EASE SpeakerLab