Vo PA Loudspeaker System Design Using Multiphysics ... · PA Loudspeaker System Design Using...
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Cms Le Mms Re R'( ) Rms L1 C1 + - Bl i c value=1 + - Vo + - F D Sd value= 1 i c u D SPEAKER Pressure in Acoustic Domain Low Pass Filter Electrical to Mechanical Domain Mechanical to Acoustic Domain u D Bl + - PA Loudspeaker System Design Using Multiphysics Simulation R. Balistreri QSC Audio Products LLC, Research and Development, Costa Mesa, CA, USA Introduction: Public Address Loudspeakers need extra design considerations if compared with normal speakers. Coverage over a certain frequency range it is important and COMSOL has the capabilities to do a whole system design simulation keeping prototype times at a minimum. Computational Methods: The simulation uses lumped circuit equivalents for the electrical to mechanical domain, (AC/DC module) and then applies the relative acceleration to the diaphragm boundary, where solves the Helmholtz equation (Acoustics module). The circuit below is one side involving the woofer side including a second order low pass filter. Results: The whole system can then be simulated and optimized with the ability to display graphs that are otherwise measured at great cost in term of resources and time. Conclusions: Beside being an excellent investigative tool, results of the simulations are close to the measurement cutting prototype work and resource investment. References: 1. L. L. Beranek, Acoustics, the Acoustical Society of America (1993) 2. A. N. Thiele, Loudspeaker in Vented Boxes Part I, part II, Journal of the Audio Engineering Society, (May-June 1971) 3. COMSOL, Lumped Loudspeaker Driver, Application Library (2014) 4. M. Kleiner, Electroacoustics, CRC Press (2013) Figure 2. Circuit Equivalent Figure 4. [email protected] and mapped response during design before (left) and after optimization (right) Figure 5. Frequency response comparison Figure 1. The model ∇∙ − 1 ∇ −q − eq 2 =Q Figure 3. Simulated response for two different woofers and filters 10k 120 100 80 60 4 Meiloon Luix TW 4V 1m 2pi MLS 00deg.mls (dB) Level, Clio MLS SPL Frequency (Hz) 2k 3k 4k 5k 6k 7k 8k 9k 20k 110 90 70 10k 120 100 80 60 4 Meiloon Luix TW 4V 1m 2pi MLS 00deg.mls (dB) Level, Clio MLS SPL Frequency (Hz) 2k 3k 4k 5k 6k 7k 8k 9k 20k 110 90 70 curve at 60 degrees on axis measurement Excerpt from the Proceedings of the 2015 COMSOL Conference in Boston
Transcript of Vo PA Loudspeaker System Design Using Multiphysics ... · PA Loudspeaker System Design Using...
CmsLe MmsRe
R'( )
RmsL1
C1
+
-
Bl ic
value=1
+
-Vo
+
-
FD Sd
value= 1
ic uD
SPEAKER
Pressure inAcoustic Domain
Low PassFilter
Electrical toMechanicalDomain
Mechanical toAcousticDomain
uD Bl
+-
PA Loudspeaker System Design Using Multiphysics SimulationR. Balistreri
QSC Audio Products LLC, Research and Development, Costa Mesa, CA, USA
Introduction: Public Address Loudspeakersneed extra design considerations ifcompared with normal speakers. Coverageover a certain frequency range it is importantand COMSOL has the capabilities to do awhole system design simulation keepingprototype times at a minimum.
Computational Methods: The simulationuses lumped circuit equivalents for theelectrical to mechanical domain, (AC/DCmodule) and then applies the relativeacceleration to the diaphragm boundary,where solves the Helmholtz equation(Acoustics module).
The circuit below is one side involving thewoofer side including a second order lowpass filter.
Results: The whole system can then besimulated and optimized with the abilityto display graphs that are otherwisemeasured at great cost in term ofresources and time.
Conclusions: Beside being an excellent investigative tool, results of the simulations are close to the measurement cutting prototype work and resource investment.
References:1. L. L. Beranek, Acoustics, the Acoustical Society of America
(1993)2. A. N. Thiele, Loudspeaker in Vented Boxes Part I, part II,
Journal of the Audio Engineering Society, (May-June 1971)3. COMSOL, Lumped Loudspeaker Driver, Application
Library (2014)4. M. Kleiner, Electroacoustics, CRC Press (2013)
Figure 2. Circuit Equivalent
Figure 4. [email protected] and mapped response duringdesign before (left) and after optimization (right)
Figure 5. Frequency response comparison
Figure 1. The model
∇ ∙ −1
𝜌𝑐∇𝑝𝑡 − q𝑑 −
𝑘eq2 𝑝𝑡
𝜌𝑐= Q𝑚
Figure 3. Simulated response for two different woofers and filters
10k
120
100
80
60
4 Meiloon Luix TW 4V 1m 2pi MLS 00deg.m ls(dB) Level, Cl io MLS SPL
Frequency ( Hz)2k 3k 4k 5k 6k 7k 8k 9k 20k
110
90
70
10k
120
100
80
60
4 Meiloon Luix TW 4V 1m 2pi MLS 00deg.m ls( dB) Level, Clio MLS SPL
Frequency ( Hz)2k 3k 4k 5k 6k 7k 8k 9k 20k
110
90
70
curve at60 degrees
on axismeasurement
Excerpt from the Proceedings of the 2015 COMSOL Conference in Boston
