An Improved Loudspeaker Frequency Response by Using a Structure of Rigid Absorptive Panel in a Vented Cabinet - new
Community Light & Sound Inc., Chester, PA, USA
When placing a loudspeaker in a cabinet, standing waves inside the cabinet affect the frequency response with ripples. This peaks and dips due to pressure cancellation inside the cabinet have an effect on the diaphragm and generating sound out from the vents. If it was in a condition of total absorption of the sound waves at the back of the diaphragm, the transducer would otherwise have a much ...
R. Magalotti 
 B&C Speakers, Bagno a Ripoli, Italy
Loudspeaker drivers are energy transducers: their main goal is to efficiently convert electrical energy to acoustic energy (sound), through the movement of mechanical parts. As such, they are prime candidates for the application of multiphysics methods and tools. The talk will outline the growing set of tools that COMSOL Multiphysics® software puts in the hands of the loudspeaker designer; ...
Y. M. Khedkar, S. B. Joshi, P. M. Pawar, B. P. Ronge
SVERI's College of Engineering, Pandharpur, Maharashtra, India
Brahmdevdada Mane Polytechnic, Solapur, Maharashtra, India
Classical hydraulic dampers are flexible devices that are used to attach a component to a mounting base. Vibration amplitude reduction can be achieved by improving the old technique of suspension by bringing in application of Magnetorheological or Electrorheological fluid in it. Due to the controllable characteristics of the material used in the classical hydraulic damper, the design and ...
R. W. Pryor ,
 Pryor Knowledge Systems, Inc., Bloomfield Hills, MI, USA
Crack detection is and has been an active field of exploration, both theoretical and applied for a number of years. It is the belief of this author that the concepts presented herein explore a new methodology for the modeling and the detection of cracks and families of cracks in crystalline solids, polycrystalline solids and high viscosity amorphous materials (glasses). In the case of the ...
P. Priya , B. D. Pant ,
 Birla Institute of Technology and Science Pilani, Pilani, Rajasthan, India
 CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan, India
In this paper, a free membrane is used as a receiver to increase the capacitance and therefore the resolution of the flow meter. For the current application, from the wavelength of sound wave in soft tissue (c= 1540 m/s) the resolution was calculated to be 0.48 mm. This gives the first Eigen frequency of the capacitive structure according to which the poly silicon membrane was designed. After ...
A. Cavuto, G.M. Revel , M. Martarelli , F. Sopranzetti 
Università Politecnica delle Marche, Ancona, Italy
Università e-Campus, Novedrate (CO), Italy
A 2D axisymmetric model was considered in order to evaluate the propagation paths of the ultrasonic waves generated inside an aluminum plate sample due to a rapid thermal expansion produced by laser pulse. Laser Doppler Vibrometer is used to experimentally validate the numerical results of the wave propagation in the material. The presented numerical model is able to identify directivity ...
S. R. Fischbach ,
 Jacobs ESSSA Group, NASA Marshall Space Flight Center, Huntsville, AL, USA
 Qualis Corporation, Huntsville, AL, USA
Combustion instability modeling of Solid Rocket Motors (SRM) remains a topic of active research. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process, acoustics, and steady-state gas dynamics. Recent advances in defining the energy transport of disturbances within steady flow-fields have been ...
V. Plessky , V. Yantchev 
 GVR Trade SA, Gorgier, Swizterland
 Individual Consultant, Sofia, Bulgaria
Electroacoustic resonators employing surface acoustic waves (SAW) are commercially widely used in RF filters, low noise frequency sources as well as various sensors. In all of these applications the resonance quality factor appears to be a limiting performance factor. Quite often practical Q factors are not limited by the materials, but by design deficiencies, enabling energy loss outside the ...
Acoustic Field Comparison of High Intensity Focused Ultrasound Using Experimental Characterization and Finite Element Simulation
J. L. Teja, A. Vera, L. Leija
Department of Electrical Engineering, Cinvestav-IPN, Mexico D.F., Mexico
High Intensity Focused Ultrasound (HIFU) is used as a noninvasive technique of tissue heating and ablation for different medical treatments. This paper presents a quantitative comparison of HIFU acoustic fields experimentally obtained versus simulated acoustic fields. Acoustic field characterization was realized in two HIFU transducers using water as a propagation medium. Also, simulations were ...
F. Malbos , M. Bogdanski , M. Strauss 
 Harman France, Paris, France
 Harman Becker Automotive Systems, Straubing, Germany
The goal of this study is to improve the audio simulation accuracy for automotive applications. COMSOL® Acoustics Module and LiveLink™ for MATLAB® were used to simulate the sound pressure generated by a loudspeaker in a car cabin. A comparison between simulated and measured sound pressures was performed. The pressure was simulated and measured on a 6 microphone arrays located at the 4 seat ...