![Page 1: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/1.jpg)
AutomatedAutomated
Loudspeaker BalloonLoudspeaker Balloon
Response MeasurementResponse Measurement
Audiomatica SRL
AES San Francisco 2008
Exhibitor Seminar ES11
Saturday, October 4, 1:00 pm — 2:00 pm
![Page 2: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/2.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
2
3D Polar Measurements3D Polar Measurements
• In this seminar we will analyze the whys and the how ofloudspeaker polar measurements
• Every aspect of the measurement process will betreated in detail (but in fact more questions thananswers will be raised...)
• The CLIO + Outline ET250-3D automatic measurementprocess will be showed
• Exportation of sets of polar data to most usedsimulation softwares formats will be showed
![Page 3: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/3.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
3
Polar Measurements AimPolar Measurements Aim
• Polar measurement sets are used for(contexts):
– Laboratory use:
• design and validation
• input for design simulation softwares
• technical documentation
– Public use:
• data sheets and catalogs
• technical publications
• models for commercial simulation softwares(EASE, CLF, ...)
![Page 4: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/4.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
4
Loudspeaker Radiation ModelLoudspeaker Radiation Model
• A loudspeaker source can be seen as a single inputmultiple output system and modeled as a point source:
with a given transfer function (linear model) for everypoint in the surrounding space S. In order to model thesystem it is necessary to sample the response into the Sspace.
S
INOUT
![Page 5: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/5.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
5
Point Source ModelPoint Source Model
• If the loudspeaker can be modeled as a point source itis possible to sample the response over a spherecentered in the source position.
S
![Page 6: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/6.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
6
How To Sample?How To Sample?
• How to sample over a sphere?
– Which spherical coordinate system?
– How many “meridians” (aka polars)?
• Use regular sampling or adaptive?
– Which resolution if regular?
– It seems also reasonable to use a finer resolutionwhere the energy content is high (can be seen alsoas a coarse resolution where the energy content islow, i.e. back emission)
– Spherical harmonics?
![Page 7: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/7.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
7
Spherical Coordinate SystemSpherical Coordinate System
Weisstein, Eric W. "Spherical Coordinates." From MathWorld - A Wolfram WebResource. http://mathworld.wolfram.com/SphericalCoordinates.html
![Page 8: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/8.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
8
Spherical Coordinate SystemSpherical Coordinate System
• We adopt this spherical coordinate system:
Is it possible to think at the source pointing its on-axis directiontowards the north pole. In this way the polars (meridians) areeffectively passing thru the poles.
x
y
zθ
φ
r
![Page 9: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/9.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
9
Simplest Method H+VSimplest Method H+V
• Simple and FAST
x
y
z
HORIZONTAL
VERTICAL
![Page 10: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/10.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
10
Simplest Method H+VSimplest Method H+V
• Sample the response over only two polars, theHorizontal and Vertical polar with a given angularresolution
– common values for theta (polar angle) resolution are 5degrees
– phi resolution is 90 degrees
• Then the missing polars are interpolated mathematically
– how to interpolate?
• Elliptical interpolation
• Smoothness of the balloon shape
– Is it the interpolation meaningful?
• Only in very simple cases
• Works only for magnitude data AFAIK
![Page 11: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/11.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
11
Why H+V is simple?Why H+V is simple?
• The measurement setup involve a single PC controlledturntable
– the PC control can be quite basic, just sending pulsesto the turntable
• The loudspeaker can be easily put on the turntable invertical and horizontal position and only two polars needto be sampled
• For a regular sampling angle of 5 degrees only 144points are needed, the procedure can be completed inless than 10 mins
![Page 12: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/12.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
12
Adding ComplexityAdding Complexity
• If we want to collect otherpolars, a single turntable is notsufficient : we need to rotatethe loudspeaker over anotheraxis
• In fact this is exactly what wedo with the H+V by placing theloudspeaker on the turntable intwo positions
• The second rotation axiscan be realized using a secondturntable or manually rotatingthe device
x
y
z
polar
azimuth
![Page 13: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/13.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
13
Big Setup ExampleBig Setup Example
![Page 14: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/14.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
14
Small Setup ExampleSmall Setup Example
![Page 15: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/15.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
15
Full 3D - Full 3D - different approachesdifferent approaches
• There are some different approaches that we need tomention apart from our 2 turntables setup:
– Arc of microphones and multichannel data acquisition
• very fast
• complex
• needs an anechoic chamber
• fixed angular resolution
– Rotating microphone
• not faster
• bit complex to get working in non-anechoic spaces
• mechanical oscillations of the long microphone boom arm
![Page 16: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/16.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
16
How ComplexHow Complex do do wewe getget??
• With two axis of rotation is it possible to sample theloudspeaker response at every point of the surroundingspherical surface
• Regularly sampling over polars leave us the possibilityto choose two different resolutions for the theta and phiangles
– as an example it is possibile to sample theta at 5 degreesand phi at 30 degrees
– is it better to choose the same resolution for the theta andphi angles?
– The AES standard currently under discussion recommendsa 5 degree resolution for both angles
![Page 17: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/17.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
17
InterpolationInterpolation, , againagain??
• At this point it must be noted that some degree ofinterpolation must be carried out at a certain point ofthe modeling process.
• If the response of the source is known over a givennumber of point over the space:– from the point of view of the measurement process we need to
decide which is the correct angular sampling angle
– it is possible here to follow the recommendations and use a 5degree angle and leave the interpolation issue to the users of themeasured data (simulation softwares)
– It has been showed by Ahnert and Feistel that the angularresolution is related to the simulation accuracy, and that given aresolution the simulation error is bounded below a certainfrequency (The Significance of Phase Data for the AcousticPrediction of Combinations of Sound Sources, AES preprint no.6632)
![Page 18: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/18.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
18
Full 3DFull 3D
• Complex and SLOW
in the worst case (no symmetry) at 5 degree resolution2664 impulse responses needs to be measured
x
y
z
![Page 19: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/19.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
19
Practical considerationsPractical considerations
• At this point we are quite confident on the fact that“high resolution” polar measurements must be carriedout in 3D with a resolution of 5 degrees...
• There is still a couple of practical problems to take intoaccount before starting to make measurements:
– Distance source-to-microphone
– Anechoic or non-anechoic space (closely related to thedistance)?
![Page 20: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/20.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
20
Source to Microphone distanceSource to Microphone distance
• It is known that the distance must be sufficiently high tomeasure the far field response. Commonly useddistance for arrayable loudspeaker ranges from 4 to 8meters.
• A greater distance reduce also the error related to apex,due to the fact that we model the source as a point andthat we rotate the source around another point that canbe non coincident with the “acoustical center”
• This can lead to measuring distances as high as 6-8meters.
![Page 21: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/21.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
21
Anechoic Anechoic or or notnot??
• In theory a big anechoic room is the solution.But it is difficult to get distances greater than 4m incommon sized anechoic chambers
• Also the measurement setup can be quite heavy andneed to be very stable, which is hard to achieve over acable floor
• A solution can be the use of semi-anechoic chambers orlow reverberation spaces (large spaces with sufficientlylow reverberation)
• A non-anechoic or semi-anechoic chamber can cut thecosts dramatically
![Page 22: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/22.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
22
PleasePlease, NO , NO OutdoorsOutdoors!!
• The temptation to perform 3D polar measurementsoutdoors is high, but the uncontrolled environmenttogether with long duration of the measurement processcan lead to big errors!
• Discarding the effect of the wind and the noise, achange in temperature will cause a phase shift:
distance 6mfrequency 10kHz
![Page 23: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/23.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
23
Not or Semi-AnechoicNot or Semi-Anechoic
• There are two issues to take into account.
– Reflections (can be eliminated by impulse windowing)
– Reverberation (can cause time alias between differentmeasurements)
![Page 24: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/24.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
24
Managing ReflectionsManaging Reflections
• Is it possible to use time windowing to get rid of theroom reflections
– The IR must be reflection free for at least T=1/f, where f isthe lowest frequency we want to measure
– In order to get this the source must be sufficiently faraway from reflective boundaries, or the boundaries mustbe treated (in the frequency range) to be absorpting.
• C.Struck, S.Temme, “Simulated Free FieldMeasurements”, JAES, Vol. 42, No. 6, 1994 June.
![Page 25: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/25.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
25
Room ReflectionsRoom Reflections
SR direct pathsource wallreflectionreceiver wall
reflection
ceilingreflection
floorreflection
lateralreflection
W D
H
h
dd
s
dr
Given the minimum frequency to bemeasured it is possible to calculatethe needed room dimensions
![Page 26: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/26.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
26
Room ReflectionsRoom Reflections
0 2.5 4.9 7.4 9.9 12 15 17 20 22 25ms
0.20
0.12
0.040
-0.040
-0.12
-0.20
Pa
CLIO
Audiomatica Srl LogChirp - Impulse Response 9-20-2008 12.59.27 PM
CH A dBSPL Unsmoothed 48kHz 4K Rectangular Start 0.00ms Stop 8.63ms FreqLO 115.94Hz Length 8.62ms
File: hidriver 0 0.mls
REFLECTIONREFLECTION
DIRECT SOUNDDIRECT SOUND
![Page 27: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/27.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
27
Managing ReverberationManaging Reverberation
• The reverberation time can cause time aliasing betweenmeasurement
• There is the need to let the energy decay sufficientlybefore taking another measurement
• The RT60 must be low at least for the frequency rangewe are measuring
• An anechoic chamber is the perfect choice, but a socalled “low reverberation chamber” can work good also
![Page 28: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/28.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
28
CLIO and 3DCLIO and 3D
• CLIO can control two turntables and automaticallyperform a set of 3D measurements
• What’s new?
– turntable control dialog*
– 3D autosave procedure*
– 3D analysis menu**
– data export in various ASCII formats**
• New turntables commercially available:
– Outline ET250-3D
– LinearX LT360
*in production **beta
![Page 29: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/29.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
29
The new Outline ET250-3DThe new Outline ET250-3D
turntableturntable• Outline recently released the new ET250-3D turntable:
![Page 30: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/30.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
30
Turntables DialogTurntables Dialog
• With this dialog it is possible toconnect and send commands tothe turntables
• Start, stop and resume anautosave procedure
![Page 31: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/31.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
31
Turntables OptionsTurntables Options
• Turntable 2 choice:
– Outline ET250-3D
– LinearX LT360
– Manual
*If a parallel port is not present on the PC it is possible to use the CLIO QC BOX model V togenerate the pulses (i.e. how to drive an old Outline ET2 without a parallel port)
• Specify which turntables isused for the polar (1) andazimuth (2) axis andcommunication setup
• Turntable 1 choice:
– Outline ET250-3D
– LinearX LT360
– TTL Pulse (legacymode*)
![Page 32: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/32.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
32
New CLIO AutosaveNew CLIO Autosave
• Two autosave methods are available:
– 1D: Basically the old CLIO method, to be used as a legacymode
– 3D: Can perform either single polar or full spheremeasurements using two turntables
![Page 33: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/33.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
33
New CLIO New CLIO AutosaveAutosave
x
y
z
r
<filename> <phi*100> <theta*100> .mls
![Page 34: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/34.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
34
New CLIO AutosaveNew CLIO Autosave
• Polar and Azimuth angular resolution is independent
– Example only horizontal and vertical polar with 5 degreeresolution:
• phi resolution = 90
• theta resolution = 5
– Example polar every 15 degrees and 5 degreesresolution:
• phi resolution = 15
• theta resolution = 5 degrees
• The SmartScan algorithm reduces polar data setmeasurement time and avoid cabling problemsscanning the polar angle back and forth
![Page 35: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/35.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
35
CLIO CLIO AutomationAutomation
• Once the turntables are connected, and the autosavesetup is done… just press GO!
• CLIO will take care of controlling the turntables, gettingthe measurements, saving the files with the namingscheme.
• It is also possible to halt the measurment process andto resume it in a later time
![Page 36: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/36.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
36
Before to Before to GO!GO!
• To avoid the unwanted reflections it is necessary tosetup the time windowing, this can be done doing anmls measurement on-axis and carefully setting the stopwindow.
• In theory it is possible to apply this windowing aftercollecting the measurement set, but to avoid toreprocess during the analysis a great number ofresponses the windowing has to be done in advance.
• It is also necessary that the disk where we want to savethe measurements has a sufficient disk space...
![Page 37: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/37.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
37
Data Set Data Set SizeSize
• The Data Set size depends on the MLS size and thenumber of measurements to be performed:
![Page 38: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/38.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
38
PressPress GO! … GO! …and Waitand Wait......
• The measurement time depends on many factors. Hereis reported an example using two Outline turntables:
![Page 39: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/39.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
39
3D 3D AnalysisAnalysis
• This is a beta version of the upgraded Waterfall andDirectivity module, basically it is a tool to check that the3D measurements has let to meaningful results
• An enhanced version with better graphics support isalready on the wish-list, at the moment it is a basicwireframe view of the magnitude balloon with controlsto rotate the balloon and to zoom in and out the balloonrange (inflate/deflate?)
![Page 40: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/40.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
40
3D 3D AnalysisAnalysis
![Page 41: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/41.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
41
Export DataExport Data
• There are some ways to use the measured data sets,some implemented into the 3D Analysis menu:
– Export to a single .xhn EASE (only magnitude) *
– Export to a single CLF v2 .tab *
– Export a single responses as time data .txt (to be importedwith EASE SpeakerLab)
• It is also possible to import the data sets into Matlab orScilab where the processing and visualization optionsare countless
* regular sampling of 5 degrees for both phi and theta angleis needed
![Page 42: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/42.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
42
MATLAB (or MATLAB (or ScilabScilab))
• Here is an example of a 3D data set measured withCLIO and visualized using MATLAB
![Page 43: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/43.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
43
Import with EASE SpeakerLabImport with EASE SpeakerLab
• EASE SpeakerLab can import CLIO time data in .txtformat, the CLIO export routine formats the file with thename requested by the SpeakerLab.
![Page 44: Automated Loudspeaker Balloon Response … Loudspeaker Balloon Response Measurement ... 0 2.5 4.9 7.4 9.9 12 15 17 20 ms 22 25 ... New CLIO Autosave](https://reader034.vdocument.in/reader034/viewer/2022051509/5af8ab937f8b9a44658cb0e7/html5/thumbnails/44.jpg)
3D Polar MeasurementsM. Bigi, D. Ponteggia - Audiomatica
44
ConclusionsConclusions
• CLIO + 2 x Outline ET250-3D can automaticallymeasure the loudspeaker 3D polar response
• The setup is very easy to manage, and measurementscan be carried out in non-anechoic spaces
• From a single measured data set it is possible to createEASE and CLF models, technical documentation andpolar plots