|
|
Near-field measurement of a modular subwoofer unit
Borodáč, Samuel ; Schimmel, Jiří (referee) ; Balík, Miroslav (advisor)
The bachleor thesis describes influence of the type of loudspeaker baffle and methods of measuring the subwoofer unit on the frequency response at low frequencies. The work describes the configuration of measurements and the procedure in the analysis software APx500, as well as the export and evaluation of measured values. Moreover, the thesis also includes the results of measurements, its brief analysis and observation of phenomena affecting the measurement of the modular frequency response of the loudspeaker unit in the near field, as well as achieving the overall resulting frequency response of the loudspeaker unit.
|
|
|
Design and Construction of Transmission Line Loudspeaker Cabinet
Dobiášovský, Jiří ; Schimmel, Jiří (referee) ; Balík, Miroslav (advisor)
Thesis is dealing with the topic of design and construction of the transmission line loudspeaker enclosures. Theoretical part is focused on speaker choice, its design elements and their influence on parameters of the speaker. Individual parameters of the speaker, mathematical equations for their determination and choice of suitable speaker for transmission line loudspeaker enclosure is furthermore discussed and defined. Principle of transmission line enclosures is discussed together with its advantages and disadvantages compared to other types of enclosures. The individual design elements and their influence on the resulting characteristics of the enclosure are described. In the practical part, with regard to the facts stated in the theoretical part of the work, a suitable speaker is selected and the subsequent design and construction of a variable transmission line speaker is described. This might serve as a teaching aid in future. Part of the work is also a description of procedures for measuring loudspeakers with multiple speakers or resonators.
|
|
|
2x400W/8 ohms end amplifier
Káňa, Lukáš ; Balík, Miroslav (referee) ; Káňa, Ladislav (advisor)
Submitted text deals with a power amplifier intended for usage in music electronics. First part is related to the common problems of low-frequency amplifiers including principles and individual circuit wiring types. Next part is related to description of self-made power amplifier including wiring scheme diagram. The end of the text concerns about mechanical construction of mounting box and design of possible module layout inside a device.
|
|
|
Implementation of time-variant convolution processor
Brhel, Tomáš ; Vrba, Kamil (referee) ; Balík, Miroslav (advisor)
In this thesis there is a design of universal time-variant convolution FIR processor. Proposed algorithm is ready to process long signals with reduced process delay. Furthermore, there are proposed methods for smooth crossfade between different impulse responses. Algorithm is implemented in Matlab environment and later as a VST plugin.
|
|
|
Subjective and Objective Assessment of Speech Quality
Bezdíček, Martin ; Balík, Miroslav (referee) ; Vondra, Martin (advisor)
This Bachelor's thesis is focused on subjective and objective methods for evaluation of speech quality. In the first part, the quality of transmitted speech signal and its distorting effects are given. Futher, subjective and objective methods for evaluation of speech are described. The objective methods: Signal to Noise Ratio (SNR), Segmental Signal to Noise Ratio (SSNR), the methods for evaluation in spectral area (Log Likelihood Ratio Measures and Cepstral Distance) and also Perceptual Evaluation of Speech Quality (PESQ). The next part deals with the correlation analysis which is used for the comparison of subjective and objective methods. In the last part of the bachelor thesis the results of subjective and objective methods are presented. Finally on the basis of correlation analysis with the results of subjective method, the best objective method is recommended.
|
|
|
Measurement of Non-Linear Properties of Loudspeakers
Friml, Vilém ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
This thesis deals with calculation of THD dependency on signal frequency and calculation of Rub & buzz distortion using MATLAB software. Thesis includes generation of signals suited for THD measurement, playback and recording using sound card and APx series 500 device. The APx device controlling and data acquisition by MATLAB is also addressed. Loudspeaker electric model is discussed for the use of Rub & buzz measurement.
|
|
|
Measurement of passive frequency crossovers for loudspeaker systems
Holínský, Jan ; Hanák, Pavel (referee) ; Balík, Miroslav (advisor)
The content of the master´s thesis is to approach the issue of measuring the characteristics of passive frequency crossover. The work describes individual types of measured characteristics and their possibility of measurement. Then the work describes design of modules for measurement characteristics of passive frequency crossover (shunt, resistive load and amplifier). These modules were made and tested for its functions. For the amplifier is then made a second design for fulfilment requirements. The second version isn’t made in this work. At the end of the work was prepared the theoretical part of the laboratory task: Measurement of characteristics of passive frequency crossover, including protocol.
|
|
|
Video sequence for supporting audio signal processing classes
Pavlikovský, Vladislav ; Schimmel, Jiří (referee) ; Balík, Miroslav (advisor)
This bachelor theses deals with making of instructional video for supporing audio signal processing classes. The theses is divided into three parts. The firs part is theoretical analysis of spatial effects, processing in time domain and processing in frequency domain. The second part is practical realization of effect panorama, moorers reberator, algorithm PSOLA and algorithm for robotization. The third part of theses is dealing with settings of Windows Media Encoder, which is suitable software for capturing video during a work on signal processing in Matlab and Simulink. The output of the thesis are two instructional videos, that should demostrate signal processing in Simulink.
|
|
|
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.
|
|
|
Variable segmentation for sound signal processing
Garai, Szabolcs ; Míča, Ivan (referee) ; Balík, Miroslav (advisor)
This paper describes the methods used mainly in the filtration of audio signals -- noise reduction. It realizes segmentation with variable lenght of segment, constant overlap add and segmentation with variable lenght of segment and overlap add. These methods are then compared with comon methods of segmentation in dependance of the lenght of segment and used window function by the thresholding method. For this purpose it uses the database of audio records. In the first part it desrcibes the technique of audio signal processing with comon method of segmentation. According to this method it continues in design of signal processing by variable segmentation method, in which it is needed to modify the shape of window function, which influences and attributes are explained in next chapter. In practical part it describes the implemented methods in MATLAB programming language with each steps of testing. It continues with chart of enclosed files and the evaluation of the results of hearing tests.
|
guest ::
