TAD Panels: An Experimental Analysis - Kinetics Noise Control · TAD (Tuned Absorber Diffuser)...
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TAD (Tuned Absorber Diffuser) Panels from Kinetics Noise Control are more effective at absorbing mid-frequency noise and scattering high frequency signals than the competition. While a published theoretical comparison between TAD Panels and another absorber/ diffuser panel described how the other panels are theoretically better 1 , it never shows any experimental test results, third party or otherwise, to back up the claim. While our competitor used a “reflection phase grating diffuser, based on number theoretic sequences” to create a “variable impedance surface”, Kinetics used a random sequence to create our design. To confirm the design, Kinetics Noise Control used an independent third-party lab to measure the full scale scattering and absorption by the International Standard Organization (ISO) international standard method in a head to head evaluation of the Kinetics TAD panel and our competitors’ panel. These reports are attached. The purpose of the Kinetics TAD panel and our competitor’s panel is to absorb mid- frequency energy and scatter high frequency energy. The most desirable panel for that application should have: 1. High mid-frequency absorption 2. Absorption quickly dropping off in higher frequencies to coefficients below 0.5 3. Increase in scattering as absorption decreases When the results form the attached test reports are plotted against each other (Fig 1), it is clear that the Kinetics TAD panel is the better performing panel based on the desired characteristics. The TAD panel’s absorption reaches a high of .96 at 800Hz while our Scattering Test Methods Kinetics chose to use the ISO 2 standard scattering test over the competing AES 3 informational document method because it has fewer disadvantages and is consid- ered more useful by acoustical room de- signers in computer modeling programs. The AES informational document method uses an acoustical goniometer to measure the reflection of sound from a test sample, usually a scale model, at discrete angles of incidence and reflection. This method will determine the acoustical diffusion co- efficients of a sample. Diffusion is defined as how evenly sound is reflected over all angles from a surface. The more uniform the reflected sound, the higher the diffu- sion coefficients. The main advantage of this method is that it shows how evenly sound is being reflected off a surface. The disadvantages of this method are that it typically only measures a single sample, it is often preformed with scale models that can produce anomalous results, it does not account for the acoustical absorption of the sample, and the results are not used in commonly available acoustic room mod- eling packages. The ISO international standard method uses a rotating turntable and a large sam- ple area to measure the average sound energy absorbed and reflected in a specu- lar manner. This method will determine the scattering coefficients of the sample. Scattering is defined as how much (or lit- tle) sound is reflected in a specular matter. The less sound reflected in a specular manner the higher the scattering coeffi- cient. The advantages of this method are that it uses a large sample to more accu- rately represent installed field conditions, takes into account acoustical absorption of the sample, and the results are used in all commonly available acoustics room mod- eling packages. The only disadvantage is Kinetics TAD Panels: An Experimental Analysis
Transcript of TAD Panels: An Experimental Analysis - Kinetics Noise Control · TAD (Tuned Absorber Diffuser)...
TAD (Tuned Absorber Diffuser) Panels fromKinetics Noise Control are more effective atabsorbing mid-frequency noise and scatteringhigh frequency signals than the competition.While a published theoretical comparisonbetween TAD Panels and another absorber/diffuser panel described how the other panelsare theoretically better1, it never shows anyexperimental test results, third party orotherwise, to back up the claim.
While our competitor used a “reflection phasegrating diffuser, based on number theoreticsequences” to create a “variable impedancesurface”, Kinetics used a random sequence tocreate our design.
To confirm the design, Kinetics Noise Controlused an independent third-party lab tomeasure the full scale scattering andabsorption by the International StandardOrganization (ISO) international standardmethod in a head to head evaluation of theKinetics TAD panel and our competitors’panel. These reports are attached.
The purpose of the Kinetics TAD panel andour competitor’s panel is to absorb mid-frequency energy and scatter high frequencyenergy. The most desirable panel for thatapplication should have:
1. High mid-frequency absorption2. Absorption quickly dropping off in higher
frequencies to coefficients below 0.53. Increase in scattering as absorption
decreases
When the results form the attached testreports are plotted against each other (Fig 1),it is clear that the Kinetics TAD panel is thebetter performing panel based on the desiredcharacteristics. The TAD panel’s absorptionreaches a high of .96 at 800Hz while our
Scattering Test Methods
Kinetics chose to use the ISO2 standardscattering test over the competing AES3
informational document method because ithas fewer disadvantages and is consid-ered more useful by acoustical room de-signers in computer modeling programs.
The AES informational document methoduses an acoustical goniometer to measurethe reflection of sound from a test sample,usually a scale model, at discrete anglesof incidence and reflection. This methodwill determine the acoustical diffusion co-efficients of a sample. Diffusion is definedas how evenly sound is reflected over allangles from a surface. The more uniformthe reflected sound, the higher the diffu-sion coefficients. The main advantage ofthis method is that it shows how evenlysound is being reflected off a surface. Thedisadvantages of this method are that ittypically only measures a single sample, itis often preformed with scale models thatcan produce anomalous results, it doesnot account for the acoustical absorptionof the sample, and the results are not usedin commonly available acoustic room mod-eling packages.
The ISO international standard methoduses a rotating turntable and a large sam-ple area to measure the average soundenergy absorbed and reflected in a specu-lar manner. This method will determinethe scattering coefficients of the sample.Scattering is defined as how much (or lit-tle) sound is reflected in a specular matter.The less sound reflected in a specularmanner the higher the scattering coeffi-cient. The advantages of this method arethat it uses a large sample to more accu-rately represent installed field conditions,takes into account acoustical absorption ofthe sample, and the results are used in allcommonly available acoustics room mod-eling packages. The only disadvantage is
Kinetics TAD Panels: An Experimental Analysis
competitor only reaches a high of .91 at630 and 800Hz. Then the Kinetics TADPanel’s absorption drops toapproximately 0.5 by 2500Hz while ourcompetitor’s panel does not decrease tothat level until 6300Hz. The TAD panel’shigh frequency (above 2500Hz) scatteringcoefficient is higher than our competitor’s.
Further, it is difficult to measure scatteringcoefficients when the absorptioncoefficients are above 0.5 since most ofthe sound is being absorbed rather thanscattered. This calls into question the
accuracy of what little high frequencyscattering our competitor’s panel doeshave.
In conclusion, Kinetics TAD Panels aremore effective at absorbing mid-frequency noise and scattering highfrequency signals than the competition.
Figure 1: Kinetics TAD Panel vs. RPG BAD Panel
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References:
1 D’Antonio, P., “Technical Bulletin on the Evaluation of the Kinetics Tuned Absorber/Diffuser Panel”.[Online] February 18, 2008, URL <http://www.rpginc.com/commercial/pdfs/Kinetics_Absorber_Diffuser_Panel.pdf >2 ISO 17497-1, “Acoustics -- Sound-scattering properties of surfaces -- Part 1: Measurement of the ran-dom-incidence scattering coefficient in a reverberation room”3 AES-4id-200 “AES information document for room acoustics and sound reinforcement systems --Characterization and measurement of surface scattering uniformity”
Kinetics Noise Control, Inc. · 6300 Irelan Place · Dublin, OH 43017-0655Telephone 614-889-0480 · FAX 614-889-0540 · Email [email protected] · www.KineticsNoise.com
NWAA Labs 25132 Rye Canyon Loop, Santa Clarita, CA 91355, Phone: (253) 973-1018
Email address…[email protected]
RANDOM- INCIDENCE SCATTERING COEFFICIENT TEST REPORT No. NW021208-1
Client: Kinetics Noise Control 6300 Irelan Place Dublin, OH 43017-0655 Test Date: 12 Feb 2008 Test Specimen: RPG BAD Panel Diffuser/ Absorber INTRODUCTION The methods and procedures used in this test conform to the provisions and requirements of ISO Procedure 17497-1, Acoustics-Sound-scattering Properties of Surfaces, Part 1, “Measurement of Random-incidence Scattering Coefficient in a Reverberation Room”. Copies of the test standard are available at www.iso.org. The test chamber is a cuboid, 871.7cm long by 541cm wide by 609.6cm high, and volume is 275 cubic meters. There are six fixed surfaces and two movable/fixed surfaces oriented as diffusers in the reverberation room. There are two sources one in each corner consisting of two Dodecahedron speakers and two sub-bass cabinets for extended low frequency capabilities. We utilize 6 Earthworks M-30 Omni directional microphones to gather the impulse responses. This test report relates only to the item(s) tested. Any advertisement that utilizes this test report or test data must not imply product certification or endorsement by NWAA Labs. DESCRIPTION OF TEST SPECIMEN The test specimen consisted of 7 RPG BAD Panels of various sizes arranged in a circle with a diameter of 10.75 ft. The samples were made of a 1/8 inch hardboard material that was punched with ½” holes arranged in a mathematical pattern and then placed on a 1 inch fiberglass panels. The shape of the sample was circular and had a nominal diameter of 10.75 Ft. The pattern is shown in the included photo. Test Results are presented on the following page. Submitted by, NWAA Labs Inc ___________________________ Ron Sauro NWAA Labs Inc
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Time Temperature (in C°) Humidity
Start 8:26 19.00Running 19.00 Running 57.8%
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Time Temperature (in C°) Humidity
Start 7:16 19.00Running 19.00 Running 58.0%
Stop 7:42 19.00 58.0%
Time Temperature (in C°) Humidity
Start 8:00 19.04 57.0%Running 19.02 Running 57.3%
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Time Temperature (in C°) Humidity
Start 6:50 19.05 58.0%Running 19.03 Running 58.0%
Stop 7:16 19.00
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NWAA Labs25132 Rye Canyon LoopSanta Clarita, CA 91355(253)-973-1018
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100Hz 0.04 0.00125Hz 0.23 0.00160Hz 0.31 0.00200Hz 0.32 0.00250Hz 0.42 0.00315Hz 0.61 0.00400Hz 0.75 0.01 NRC 0.75500Hz 0.83 0.01630Hz 0.91 0.00 SAA 0.74800Hz 0.91 0.101000Hz 0.90 0.001250Hz 0.82 0.121600Hz 0.86 0.032000Hz 0.77 0.002500Hz 0.71 0.043150Hz 0.70 0.094000Hz 0.65 0.095000Hz 0.57 0.086300Hz 0.53 0.118000Hz 0.41 0.0010000Hz 0.54 0.12
NWAA Labs25132 Rye Canyon LoopSanta Clarita, CA 91355(253)-973-1018
RPG BAD Panels
NWAA Labs 25132 Rye Canyon Loop, Santa Clarita, CA 91355, Phone: (253) 973-1018
Email address…[email protected]
RANDOM- INCIDENCE SCATTERING COEFFICIENT TEST REPORT No. NW021308-1
Client: Kinetics Noise Control 6300 Irelan Place Dublin, OH 43017-0655 Test Date: 13 Feb 2008 Test Specimen: Kinetics Noise Control TAD Panel Diffuser/ Absorber INTRODUCTION The methods and procedures used in this test conform to the provisions and requirements of ISO Procedure 17497-1, Acoustics-Sound-scattering Properties of Surfaces, Part 1, “Measurement of Random-incidence Scattering Coefficient in a Reverberation Room”. Copies of the test standard are available at www.iso.org. The test chamber is a cuboid, 871.7cm long by 541cm wide by 609.6cm high, and volume is 275 cubic meters. There are six fixed surfaces and two movable/fixed surfaces oriented as diffusers in the reverberation room. There are two sources one in each corner consisting of two Dodecahedron speakers and two sub-bass cabinets for extended low frequency capabilities. We utilize 6 Earthworks M-30 Omni directional microphones to gather the impulse responses. This test report relates only to the item(s) tested. Any advertisement that utilizes this test report or test data must not imply product certification or endorsement by NWAA Labs. DESCRIPTION OF TEST SPECIMEN The test specimen consisted of 7 Kinetics TAD Panels of various sizes arranged in a circle with a diameter of 10.75 ft. The samples were made of a 1/8 inch hardboard material that was punched with ½” holes arranged in a mathematical pattern and then placed on a 1 inch fiberglass panels. The shape of the sample was circular and had a nominal diameter of 10.75 Ft. The pattern is shown in the included photo. Test Results are presented on the following page. Submitted by, NWAA Labs Inc ___________________________ Ron Sauro NWAA Labs Inc
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Time Temperature (in C°) Humidity
Start 5:30 18.94Running 18.94 Running 57.8%
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Time Temperature (in C°) Humidity
Start 4:19 18.95Running 18.94 Running 58.0%
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Time Temperature (in C°) Humidity
Start 5:04 18.99 57.0%Running 18.97 Running 57.3%
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Start 3:53 19.02 58.0%Running 18.98 Running 58.0%
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100Hz 0.04 0.00125Hz 0.26 0.00160Hz 0.31 0.00200Hz 0.33 0.00250Hz 0.40 0.02315Hz 0.63 0.00400Hz 0.82 0.00 NRC 0.70500Hz 0.94 0.00630Hz 0.95 0.00 SAA 0.74800Hz 0.96 0.111000Hz 0.91 0.121250Hz 0.79 0.061600Hz 0.73 0.072000Hz 0.63 0.022500Hz 0.51 0.103150Hz 0.51 0.114000Hz 0.42 0.185000Hz 0.35 0.176300Hz 0.41 0.178000Hz 0.32 0.1710000Hz 0.40 0.25
NWAA Labs25132 Rye Canyon LoopSanta Clarita, CA 91355(253)-973-1018
Kinetics Noise Control TAD Panels
