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Two-way stereo speaker system
Kočvara, Pavel ; Polák, Ladislav (referee) ; Kratochvíl, Tomáš (advisor)
The Bachelor thesis deals with design of a passive two-way stereo speaker system with performance 50 W RMS / 8 for normal domestic use. With respect to its sensitivity 90 dB/W/m mid-range speakers Beyma 5MP50/N and tweeter Beyma T2030 were used. The enclosure is a type of bass-reflex and it is made of MDF material with internal damping from polyurethane coat.
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Automotive audio amplifier and subwoofer
Kolka, René ; Šotner, Roman (referee) ; Dřínovský, Jiří (advisor)
This thesis deals with the project of two performance amplifiers for a subwoofer and for four basic car loud-speakers. The following part of the thesis is dealing with the power circuits of the amplifiers. The control of the amplifiers is realized by processor. The thesis is also dealing with the problems caused by sound system installation in a car, and concerns mainly with the boosters position and with producing high quality subwoofer and baffle-board.
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Laboratory design of a speaker system
Šulc, Martin ; Schimmel, Jiří (referee) ; Špiřík, Jan (advisor)
The bachelor thesis deals with the project of loudspeakers using freely available computer softwares. The thesis is focused on creation of a laboratory exercise called Laboratory design of a speaker system. The basic quantities describing acoustic wave motion and the principles of acoustic spread are explained there. There are also described different parts of loudspeakers like cabinets, loudspeaker drivers and electrical crossovers. Different softwares were chosen for the design. The descriptions of the most convenient programs for the laboratory exercises are introduced in the thesis. The laboratory exercise is devided into three parts. In the first part there is a brief theoretic introduction, the second part describes the control of the chosen software and the third part deals with the topic of this thesis. I have chosen two different sreeware softwares the most convenient for the construction of loudspeakers.
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Loudspeaker design for home environment
Šafer, Radim ; Schimmel, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
The subject of my bachelor‘s thesis is a design of the loudspeaker for home listening. Foremost I focused on simulations of the loud-speakers, which I use to a design itself. The loudspeaker is a two-way and stereophonic, which is optimised for a woofer Beyma 6B30/P and a tweeter Beyma T2010. The enclosure is closed, made of the M.D.F. material. The vibration damping is ensured by a polyester damping cottonwool. The maximum standardised wattage of the loudspeaker is 50 W, nominal impedance is 8 ?, internal capacity is around 15 litres, sensitivity 90 dB and weight 10 kg.
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Loudspeaker Box for Laboratory Measurements of Loudspeaker Impedance
Nevole, Tomáš ; Káňa, Ladislav (referee) ; Schimmel, Jiří (advisor)
In this thesis there are solved problems of design and construction of a universal modular loudspeaker box, which should serve for laboratory measurements of broadband electro-magnetic loudspeaker’s impedance. These measurements should demonstrate how the electric parameters are changed by changing the acoustic impedance of surrounding into which the speaker transmits. In the first part there is explained necessary theory for solving the task, such as way of sound’s transmission in the environment, variable sorts of speakers and their characteristics. A special focus is given to description of the electro-magnetic speaker’s parameters and construction that was used for the loudspeaker box. Then there are introduced needed mathematical formulas for algebraic design of the loudspeaker box, various types of the loudspeaker boxes (open, closed, vented) and their parameters. In this thesis there is also solved the problem with leaks and settled the matter, if it is better to build one modular box or 2 or 3 separate boxes. Most important characteristics are the impedance characteristics for this thesis but the SPL characteristics are also included. Unfortunately the simulating programs couldn’t generate the hodographs of impedance. After the algebraic calculations, in the thesis there are presented outputs from simulation programs Unibox 408 and WinISD 0.6. The outputs also are compared with the algebraic calculations. In the last part of the thesis there is already described the own construction of the loudspeaker box and presented results from the box’s measuring in the anechoic chamber (in the laboratory of electro-acoustic). The measuring of the modular impedance characteristic was realized on the single speaker and all the boxes. The measuring of the SPL (sound pressure level) characteristic was realized on the boxes only. All these results are compared with the calculations and simulations and the inaccuracies are substantiated in the end. The comparing of the manufacturer’s characteristics with the measured characteristics is also included.
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Loudspeaker Box with Variable Crossover Frequency
Tomášek, Martin ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
This bachelor´s thesis deals with middle-sized loudspeaker system in D´Appolito configuration. The aim of this thesis is to design and to realize the loudspeaker system, which includes selection of suitable loudspeakers and their position in designed baffle including design of variable crossover frequency. The text is divided into a few sections, where are the points of this project described. In the first half there are briefly described basic principles of loudspeakers and design loudspeaker systems, especially 2-way loudspeakers, and specific properties of D´Appolito configuration. Then there are described principles of frequency crossovers used in loudspeaker systems and what is expected for their construction. In the second half, there is described realization of baffle itself and variable frequency crossover. Because this thesis concurs to semestral thesis, there is also a chapter about simulation. In the end there are diagrammatized the measured data of frequency and dispersion characteristics and a few dispersion characteristics for different crossing frequences.
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Loudspeaker System for Laboratory Measurements of Polar Patterns
Morkus, Filip ; Káňa, Ladislav (referee) ; Schimmel, Jiří (advisor)
In the first part the attention is aiming to the choice of suitable loudspeakers. For this choice it was necessary to set required criteria and parameters. The aim of the system was to have as wide reproducibility range of frequency as possible but on the other hand not to be too large. The other criterion was the quality of the loudspeakers and its price. In the second part there was frequency crossover suggested according to the parameters of the chosen loudspeakers. This was suggested for low frequency spectrum as well as for high frequency spectrum. When determining the dividing frequency there were thought over producer’s recommendations and frequency characteristics of the loudspeakers so that the dividing frequency was not set in the place where the loudspeaker does not have “constant” character. The third part concerns the construction of the loudspeaker case. There one can find more details about the construction of the loudspeaker system called D´Appolito and its constructional requirements. This part was kept to the previous parts because integrating “D´Appolito” needs setting the distance between the loudspeakers according to the dividing frequency. It was also necessary to count with their size. According to the loudspeakers parameters it was possible to calculate the capacity of the loudspeaker case, also its shape was said and geometric proportions were calculated. Then everything was simulated in suitable software. In the last part the complete loudspeaker system was measured in an anechoic room. There were the direction characteristics and frequency characteristics measured there. The results of the measuring were compared with the software simulations.
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Design and Implementation of Active Loudspeaker System with Digital Input
Uchytil, Filip ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
The work is focused on a design of an active loudspeaker system with a bi-amp amplifier and a digital input. There is described the theory of a loudspeaker enclosure design and its practical implementation. Furthermore the work deals with a design and construction of input circuits such as a preamplifier, Baxandall tone control, active crossover, all-pass filter and S/PDIF. On the basis of the amplifier´s theory the optimal construction of amplifiers and their design are selected. The complex design of the loudspeaker box is devised so that it would reach a maximum acoustic power during the preservation of a low distortion.
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Audio speaker system with baffle made from alternative materials
Hüttl, Ondřej ; Schimmel, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
This thesis firstly consists of an analysis and a description of materials suitable for construction of loudspeaker enclosures and a design of the loudspeaker system with the enclosure made of a synthetic stone. Electro – acoustics drivers have been described with a focus to a frequency range, a principle and a construction for an explanation of their function. Drivers based on electrodynamic principle have been described closely. An analysis of materials used for the loudspeaker enclosure production has been done and tradicional and alternative materials have been described as well. Specific modulus, density and stiffness have been taken as an objective evaluative criterion. An evaluation indicates appropriate properties of plastic, aluminum and stone based materials. The function and kinds of loudspeaker enclosures have been described. The function, properties and design of a vented box loudspeaker system have been described closely. The last part of this thesis is individual design of a two-way vented box loudspeaker system with the enclosure made of synthetic stone. A simulation of a driver behavior built in the enclosure and compensation circuits and crossovers design and simulation have been done. The enclosure has been designed with high stress to minimize negative effect of the enclosure to the final sound quality.
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