Education Resources – NEXO https://www.nexo-sa.com NEXO Fri, 23 Feb 2024 09:09:02 +0000 en-US hourly 1 https://wordpress.org/?v=6.0.9 https://www.nexo-sa.com/wp-content/uploads/cropped-nexo-icon-32x32.png Education Resources – NEXO https://www.nexo-sa.com 32 32 Complete Modeling of a Vented Box Loudspeaker in COMSOL Multiphysics® https://www.nexo-sa.com/complete-modeling-of-a-vented-box-loudspeaker-in-comsol-multiphysics/ https://www.nexo-sa.com/complete-modeling-of-a-vented-box-loudspeaker-in-comsol-multiphysics/#respond Fri, 23 Feb 2024 08:59:02 +0000 https://www.nexo-sa.com/?p=88311 Continue reading "Complete Modeling of a Vented Box Loudspeaker in COMSOL Multiphysics®"]]> This paper describes the use of COMSOL Multiphysics® during the design of a vented box loudspeaker. Several templates have been created to model the different needs of a complete design. Based upon those templates a real box has been prototyped, measured and confronted to simulation.
The cabinet prototyped may be described as a vented box design, featuring two low frequency drivers mounted in a “V Shape” with a horn loaded compression driver. Several uses of
COMSOL Multiphysics® have been considered in this study.

 

  • Optimization of the directivity of the V shape design with different configurations in 3D.
  • Optimization of the tuning and shapes of the vent.
  • Optimization of the horns polar pattern and radiating impedance.
  • Calculation of the acoustic modes within the box.
  • Calculation of the structural modes of the box itself.

Most of the models have been confronted to real measurements of a prototype made with a fast prototyping machine.

]]> https://www.nexo-sa.com/complete-modeling-of-a-vented-box-loudspeaker-in-comsol-multiphysics/feed/ 0 Analysis of Non Linear Distrortion in Compression Drivers https://www.nexo-sa.com/analysis-of-non-linear-distrortion-in-compression-drivers/ https://www.nexo-sa.com/analysis-of-non-linear-distrortion-in-compression-drivers/#respond Tue, 05 Dec 2023 15:01:39 +0000 https://www.nexo-sa.com/?p=86429 Continue reading "Analysis of Non Linear Distrortion in Compression Drivers"]]> This paper shows the main cause of distortion in compression drivers is the air nonlinearity that occurs in the horn and not in the transducer. This nonlinearity is mainly a result of the modulation of the celerity of the sound wave by the acoustic velocity. Models have been designed and successfully experimented by precorrecting the audio signal in the digital domain.

]]> https://www.nexo-sa.com/analysis-of-non-linear-distrortion-in-compression-drivers/feed/ 0 Linear phase implementation in loudspeaker systems – measurements, processing methods and application benefits https://www.nexo-sa.com/linear-phase-implementation-in-loudspeaker-systems-measurements-processing-methods-and-application-benefits/ https://www.nexo-sa.com/linear-phase-implementation-in-loudspeaker-systems-measurements-processing-methods-and-application-benefits/#respond Tue, 05 Dec 2023 15:00:04 +0000 https://www.nexo-sa.com/?p=86421 Continue reading "Linear phase implementation in loudspeaker systems – measurements, processing methods and application benefits"]]> The aim of this paper is to present a new generation of EQ. It provides a way to ensure phase compatibility from 20 Hz to 20 kHz over a range of different speaker cabinets. This method is based on a mix of FIR filters and IIR filters. The use of FIR filters allows a tuning of the phase independently from magnitude and allows an acoustic linear phase above 500 Hz. All targets used to compute FIR coefficient are based upon extensive measurement and subjective listening tests. A template has been set to normalize the crossover frequencies in the low range, enabling compatibility of every sub-bass with the main cabinets.

]]> https://www.nexo-sa.com/linear-phase-implementation-in-loudspeaker-systems-measurements-processing-methods-and-application-benefits/feed/ 0 On the Impact of Neglecting Accurate Sound Speed-Models on the Cylinder Measurement Method for Directivity Balloons https://www.nexo-sa.com/on-the-impact-of-neglecting-accurate-sound-speed-models-on-the-cylinder-measurement-method-for-directivity-balloons/ https://www.nexo-sa.com/on-the-impact-of-neglecting-accurate-sound-speed-models-on-the-cylinder-measurement-method-for-directivity-balloons/#respond Tue, 05 Dec 2023 14:56:54 +0000 https://www.nexo-sa.com/?p=86413 Continue reading "On the Impact of Neglecting Accurate Sound Speed-Models on the Cylinder Measurement Method for Directivity Balloons"]]> The far-field acoustical transfer function of an electroacoustic device, such as a loudspeaker, is of fundamental importance in acoustic modelling software to predict the resulting sound field produced by multiple devices in 3D space. This dataset, commonly known as a directivity balloon, is usually acquired through time-consuming, sophisticated measurement techniques involving extensive hardware and dedicated post-processing algorithms. Additionally, such dataset is usually compensated for the effect of acoustical propagation to reference the magnitude and phase values to conventional distances. This works investigates the effects of propagation compensation within the cylinder measurement method for directivity balloons, specifically considering the use of improper sound speed values relative to the ambient conditions during the measurement process. The importance of employing environmental parameter-dependent models for the propagation speed of sound in this type of measurement is emphasized, as to maintain high accuracy in the final directivity data phase response.

]]> https://www.nexo-sa.com/on-the-impact-of-neglecting-accurate-sound-speed-models-on-the-cylinder-measurement-method-for-directivity-balloons/feed/ 0 CAD of Dedicated High Power Modular Loudspeaker Cabinets for Concert Sound Reinforcement https://www.nexo-sa.com/cad-of-dedicated-high-power-modular-loudspeaker-cabinets-for-concert-sound-reinforcement/ https://www.nexo-sa.com/cad-of-dedicated-high-power-modular-loudspeaker-cabinets-for-concert-sound-reinforcement/#respond Tue, 05 Dec 2023 14:55:12 +0000 https://www.nexo-sa.com/?p=86405 Continue reading "CAD of Dedicated High Power Modular Loudspeaker Cabinets for Concert Sound Reinforcement"]]> User requirements for modern modular high-power concert sound reinforcement systems dictate new advances in loudspeaker cabinet design. An elaborate C.A.D. system is set up. The results lead to specific solutions used in prototypes, whose performance is measured and compared to simulations. The complex transference and impedance data are then stored in the C.A.D. system for filter design and optimization. Use and performance of new cabinets in high power sound reinforcement are discussed.

]]> https://www.nexo-sa.com/cad-of-dedicated-high-power-modular-loudspeaker-cabinets-for-concert-sound-reinforcement/feed/ 0 Cylinder Measurement Method for Directivity Balloons https://www.nexo-sa.com/cylinder-measurement-method-for-directivity-balloons/ https://www.nexo-sa.com/cylinder-measurement-method-for-directivity-balloons/#respond Tue, 05 Dec 2023 14:50:49 +0000 https://www.nexo-sa.com/?p=86397 Continue reading "Cylinder Measurement Method for Directivity Balloons"]]> There are several ways to obtain the set of frequency responses all around a loudspeaker, the so-called directivity balloon which provides useful knowledge about the loudspeaker radiation behavior. In this paper, a novel method for collecting far-field directivity balloon datasets is presented. This alternative method builds on traditional polar measurements and proved to be practical both in terms of measurement time and equipment set-up. By cleverly combining datasets and by using far-field wave propagation, datasets in cylindrical coordinates are created and then projected on a sphere. Eventually, using a spherical interpolation, the directivity balloon is obtained.

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