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Loudspeaker System for Reproduction of Low Frequencies with Directional Radiation
Skvaril, Šimon ; Husník, Libor (referee) ; Schimmel, Jiří (advisor)
Final product of this work is design of speaker baffle which will have directional radiation at low frequencies. In the course of the work, propagation of sound waves and their beaviour at obstacles are described. The computational method FDTD and the K-wave toolkit for MATLAB, which uses this method, are described. In MATLAB a virtual model of speaker baffle is created and proposed solution is verified. Next step is creation of scaled model of speaker baffle on which agreement of theoretical computations with real-world measurment is verified. Final step is creation of prototype of speaker baffle,, whose parameters are measured, including polar response.
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Universal passive frequency crossover - laboratory device
Pacek, Dominik ; Hanák, Pavel (referee) ; Balík, Miroslav (advisor)
The aim of this work is to theoretically outline the issues associated with design of a passive crossover network in the context of speaker system design and the solutions to the mentioned issues.The practical part of the work deals with the design of a laboratory passive crossover network, it’s construction and creation of laboratory task utilizing the crossover network for teaching loudspeakers and speaker systems course.
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Standard baffle - laboratory device
Hodinka, Tomáš ; Říha, Kamil (referee) ; Balík, Miroslav (advisor)
The purpose of this project is the design and the construction of a laboratory preparation for loudspeaker measurements, a standard baffle. Standard baffle is a rectangular panel with a loudspeaker placed eccentrically. Measurements with this baffle are then done in an anechoic chamber. The main purpose of a standard baffle is the ability to measure loudspeakers without the effect, that is caused by the pressure properties of a closed baffle and without an acoustic short circuit. The standard baffle is designed, so that it is self-supporting, transferable by 2 people, easy to be stored, modular and able to support loudspeakers that are up to 12 inches in diameter. The designed baffle is detachable into 3 parts. The base, the panel, and the inserts. The base is a big, heavy board with a key on the upper side. This key fits into a key groove in the panel and that allows the two parts to assemble. The plane is made of four layers of different types of plywood. That allows the design to make a compromise between the toughness and weight. The inserts are designed, so that the replacement and manipulation of loudspeakers during measurement are as past and as simple as possible. During measurement the loudspeakers are mounted in their respective inserts, which can be mounted and dismounted from the standard baffle without any tools. The test measurements demonstrated that the standard baffle is unsuitable for reference measurements. Resonance of the plane, reflections from the base, refractions from the outer edges of the baffle and potentially different causes unduly distort the results of measurements. These distortions are displayed with a considerable consistency even between different loudspeakers. This indicates that these distortions could be filtered oud by, for example, using a specialized software.
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Variable Two-Way Loudspeaker Cabinet - Laboratory Tool
Rehák, Jan ; Schimmel, Jiří (referee) ; Balík, Miroslav (advisor)
The objective of this work is to build a two-way loudspeaker system that will enable changing loudspeaker topology in both vertical and horizontal axes and to suggest two laboratory tasks. The theoretical part of this work will briefly discuss loudspeaker crossovers. Then it will discuss how topology of loudspeakers in a loudspeaker system can affect its behavior at crossover frequency. Frequency characteristics of various loudspeaker baffles will be shown. On these, the effect of a baffle’s exterior on its behavior will be discussed. A two-way loudspeaker system will be designed. The construction process and drawings of each part are also included in this work. The finished product will be tested and, following from these tests, a conclusion will be drawn about the validity of the theoretical assumptions of its design. After that, appropriate parameters of a crossover for the two-way loudspeaker system will be chosen.
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Subwoofer for PA applications
Tylich, Ondřej ; Červinka, Dalibor (referee) ; Martiš, Jan (advisor)
The content of the bachelor´s thesis is theoretical knowledge in the field of loudspeaker baffles, their construction and design of the subwoofer according to the assignment. The work describes various types of used loudspeaker baffles. Their properties are defined for each of them. Some of the simulation programs are used for proper design. A suitable speaker is selected for the subwoofer application in PA technology. The parameters of the selected loudspeaker are verified by measurement. Based on these parameters, the design of the selected loudspeaker is calculated. Furthermore, the thesis addresses deals with the complete design process of the baffle for the selected speaker and its subsequent construction. After the construction, the port is tuned to the selected parameters. The resulting parameters of the designed subwoofer are verified by measuring the amplitude and frequency characteristics.
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Active Loudspeaker Crossover with DSP
Václavík, Jiří ; Fedra, Zbyněk (referee) ; Povalač, Aleš (advisor)
Semestral thesis is devoted to mapping and verification technologies for the project active loudspeaker crossover using DSP. Three way systém will use open baffle. Design of analog crossover is complex due to the need of compensating for acoustic short circuit and properties of laudspeakers.
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Simulation of Sound Field of Multiple Sound Sources
Kohoutek, Jan ; Kurc, David (referee) ; Schimmel, Jiří (advisor)
The main task of this bachelor thesis is description of interaction of sound waves in field. To understand the whole topic important physical laws related to sound waves propagation are defined. It also deals with frequency and directional response of ideal point source which compares with real measured responses of direct-radiating electrodynamic loudpeaker. Thesis are shown some examples of sound fields on which are specified their behavior. It also desribe main properties for right functionality of line-array source. In practical part are measured acoustic pressure values which lead to creating a interpolation map of sound pressure level. This obtained map was compared with theoretical acoustic field. Part of this bachelor thesis is program which enable to simulate acoustic field created under variable sound and environment properties.
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Three-way stereo speaker system with bassreflex
Burget, Jan ; Schimmel, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
This bachelor‘s thesis contains complete design of three-way stereophonic loudspeaker sound system with bassreflex. There is detailed description of selection of acoustic transducers, their measurements and adjustments. As an integral part of this seminar study is design of loudspeaker baffle and calculations or simulation of bassreflex. And further,this study also deals with a design of loudspeaker crossovers and their simulation. The study contains structural elements as a PCB (printed circuit board) or 3D pattern and drawings of loudspeaker box. KEYWORDS
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Power audio amplifier with two-way speaker system
Rystvej, Matej ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
The aim of this bachelor thesis was a design of a stereo amplifier with an appropriate loudspeaker system for home listening. The amplifier has the ability to be switched over between high and low output power mode. This means it is possible to be used also with an other loudspeaker system with lower input power rating, and it will be prepared for possible future implementation of an active frequency filter, which will fit the frequency response to this designed loudspeaker system by amplifying some frequencies. This thesis contains design of the softstart circuit, power amplifier, preamplifier circuit, the output power switch, the delayed loudspeaker connecting circuit and the loudspeaker system.
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