Cylindrical Subwoofer
In this model, the acoustic field inside and outside a down-firing subwoofer is computed. This model is set up in 2D axisymmetry using the Pressure Acoustics application mode. The modeled physical domain is a hemisphere with a radius of 1 m. To minimize the effect of non-physical reflections at the exterior boundary of this domain, an absorbing Perfectly Matched Layer (PML) is added. The ...
Small Concert Hall Analyzer
Designing structures and open spaces with respect to sound quality is important for concert halls, outdoor environments, as well as the rooms of a house. You can simulate acoustics in the high-frequency limit, where the wavelength is smaller than the geometrical features, with ray acoustics. This application analyzes the acoustics of a small concert hall using the *Ray Acoustics* physics ...
Loudspeaker Driver - Transient Analysis
In this model, a full transient analysis of a loudspeaker driver is performed, which allow the modeling of nonlinear effects. It extends the linear frequency domain analysis done in the Loudspeaker Driver tutorial model. The analysis accounts for nonlinear behavior of the soft iron in the magnetic system, geometric nonlinearities in the structures, and nonlinear effects due to the topology ...
Piezoelectric Tonpilz Transducer with a Prestressed Bolt
A tonpilz transducer is used for relatively low frequency, high power sound emission. It is one of the popular transducer configurations for SONAR applications. The transducer consists of piezoceramic rings stacked between a head mass and a tail mass which are connected by a central bolt. This example shows how to incorporate the effect of a pre-tension in the bolt. The bolt geometry is ...
Shape Optimization of a Tweeter Waveguide
This application illustrates how to use COMSOL’s optimization capabilities to automatically develop novel designs satisfying critical design constraints. The model optimizes a simple speaker geometry. Examples of constraints could include the radius of the loudspeaker or a desired minimum achievable sound-pressure level. To exemplify the optimization capabilities this application studies the ...
Acoustic Reflections off a Water-Sediment Interface
This model determines the reflection coefficient of plane acoustic waves, at different frequencies and at different angles of incidence, off a water-sediment interface. The ability of the Poroelasitc Waves interface to model the coupled acoustic and elastic wave in any porous substance (Biot's theory) is used to describe the water-sediment system. The model results are in good agreement with ...
Dispersion Curves for a Fluid-Filled Elastic Pipe
The dispersion curves for a fluid-filled pipe with elastic walls are computed and compared with the analytical results for a pure elastic and an acoustic waveguide, respectively. Results show good agreement and also provide insight into the dynamics of the fluid-filled pipe at low and midrange frequencies.
One-Family House Acoustics
This model shows an application of the Acoustic Diffusion Equation physics interface. The acoustics in a two story one-family house consisting of 10 rooms is analyzed. The steady state sound pressure level (acoustic energy density) distribution is analyzed for a sound source located in the main living room. The reverberation time T60 of the different coupled rooms is then studied using the ...
Axisymmetric Condenser Microphone
This is a model of a condenser microphone with a simple axisymmetric geometry. The model aims to give a precise description of the physical working principles of such a microphone. The condenser microphone is considered to be the microphone with highest quality when performing precise acoustical measurements and with high-fidelity reproduction properties when performing sound recordings. This ...
Generic 711 Coupler—An Occluded Ear-Canal Simulator
This is the model of an occluded ear canal simulator (a generic 711 coupler). Besides certain details the geometry corresponds to the Brüel & Kjær Ear Simulator Type 4157. The real life couplers are used for simulating the acoustics of a standardized human ear canal and can be used for measurements on all sorts of devices. They are widely used in the hearing aid industry but also as ear ...