Hardware for music sequencer

Zadatak ovog završnog rada je izrada elektroničkog sklopovlja muzičkog sekvencera. Korištenjem mikrokontrolera Raspberry Pi 3 model B, te korištenjem diskretnih logičkih sklopova projektiran je i realiziran muzički sekvencer. Audio datoteke se reproduciraju pomoću polja senzora veličine 8*8 pri čemu je indikacija toka vremena realizirana svjetlećim diodama.Assignment for this Bachelor Thesis is designing an electronics hardware for music sequencer. System is using microcontroler Raspberry Pi 3 model B. Music sequencer is made by using Raspberry Pi and discrete logic gate. Audio files are played by using home-made matrix of sensors (8*8), with the time course being shown with LEDs

Two-way active loudspeaker

U ovom radu realiziran je sustav aktivnog dvostaznog zvučnika. Za konstrukciju zvučnika bilo je potrebno izraditi kutiju na niskotonski zvučnik i pomični sustav kutije visokotonskog zvučnika. Potrebne naponske razine dobivene su kupnjom gotovog ispravljača napona za najviši potrebni iznos, te uz korištenje linearnih regulatora napona dobivene su ostale potrebne razine. U sustavu skretnice signala implementirano je zbrajalo lijevog i desnog kanala ulaznog signala uz zaštitni pojasnopropusni filtar, regulator razine signala, niskopropusni filtar i visokopropusni filtar s atenuacijom razine visokotonskog signala, i sklop za generiranje diferencijalnog signala. Pločica sustava skretnice realizirana je metodom dead-bug. Za pojačalo korišten je gotov čip pojačala D klase na odgovarajućoj tiskanoj pločici za konfiguraciju s dva ulazna diferencijalna signala i izlaznom BTL aplikacijom. Na sustavu su napravljena osnovna elektronička i akustička mjerenja, kojima se poboljšala kvaliteta kompletnog sustava.This graduation thesis is an implementation of an active two-way loudspeaker system. For the construction of the speaker, it was necessary to make a box for the subwoofer and a movable system for the tweeter box. The required voltage levels were obtained by purchasing a ready-made voltage rectifier for the highest required voltage, and with the use of linear voltage regulators, the other required levels were obtained. The signal crossover system is made with an adder of the left and right channels of the input signal with a protective bandpass filter, a signal level regulator, a low-pass filter and a high-pass filter with attenuation of the treble level, and a circuit for generating a differential signal. The circuit board for the crossover was implemented using the dead-bug method. For the amplifier, a ready-made D-class amplifier chip was used on a suitable configuration PCB with two input differential signals and an BTL output application. Basic electronic and acoustic measurements were made on the system, which improved the quality of the complete system

Two-way active loudspeaker

U ovom radu realiziran je sustav aktivnog dvostaznog zvučnika. Za konstrukciju zvučnika bilo je potrebno izraditi kutiju na niskotonski zvučnik i pomični sustav kutije visokotonskog zvučnika. Potrebne naponske razine dobivene su kupnjom gotovog ispravljača napona za najviši potrebni iznos, te uz korištenje linearnih regulatora napona dobivene su ostale potrebne razine. U sustavu skretnice signala implementirano je zbrajalo lijevog i desnog kanala ulaznog signala uz zaštitni pojasnopropusni filtar, regulator razine signala, niskopropusni filtar i visokopropusni filtar s atenuacijom razine visokotonskog signala, i sklop za generiranje diferencijalnog signala. Pločica sustava skretnice realizirana je metodom dead-bug. Za pojačalo korišten je gotov čip pojačala D klase na odgovarajućoj tiskanoj pločici za konfiguraciju s dva ulazna diferencijalna signala i izlaznom BTL aplikacijom. Na sustavu su napravljena osnovna elektronička i akustička mjerenja, kojima se poboljšala kvaliteta kompletnog sustava.This graduation thesis is an implementation of an active two-way loudspeaker system. For the construction of the speaker, it was necessary to make a box for the subwoofer and a movable system for the tweeter box. The required voltage levels were obtained by purchasing a ready-made voltage rectifier for the highest required voltage, and with the use of linear voltage regulators, the other required levels were obtained. The signal crossover system is made with an adder of the left and right channels of the input signal with a protective bandpass filter, a signal level regulator, a low-pass filter and a high-pass filter with attenuation of the treble level, and a circuit for generating a differential signal. The circuit board for the crossover was implemented using the dead-bug method. For the amplifier, a ready-made D-class amplifier chip was used on a suitable configuration PCB with two input differential signals and an BTL output application. Basic electronic and acoustic measurements were made on the system, which improved the quality of the complete system

The Performance of Inertial Measurement Unit Sensors on Various Hardware Platforms for Binaural Head-Tracking Applications

Binaural synthesis with head tracking is often used in spatial audio systems. The devices used for head tracking must provide data on the orientation of the listener’s head. These data need to be highly accurate, and they need to be provided as fast and as frequently as possible. Therefore, head-tracking devices need to be equipped with high-quality inertial measurement unit (IMU) sensors. Since IMUs readily include triaxial accelerometers, gyroscopes, and magnetometers, it is crucial that all of these sensors perform well, as the head orientation is calculated from all sensor outputs. This paper discusses the challenges encountered in the process of the performance assessment of IMUs through appropriate measurements. Three distinct hardware platforms were investigated: five IMU sensors either connected to Arduino-based embedded systems or being an integral part of one, five smartphones across a broad range of overall quality with integrated IMUs, and a commercial virtual reality unit that utilizes a headset with integrated IMUs. An innovative measurement method is presented and proposed for comparing the performance of sensors on all three platforms. The results of the measurements performed using the proposed method show that all three investigated platforms are adequate for the acquisition of the data required for calculating the orientation of a device as the input to the binaural synthesis process. Some limitations that have been observed during the measurements, regarding data acquisition and transfer, are discussed

The Accuracy of Dynamic Sound Source Localization and Recognition Ability of Individual Head-Related Transfer Functions in Binaural Audio Systems with Head Tracking

The use of audio systems that employ binaural synthesis with head tracking has become increasingly popular, particularly in virtual reality gaming systems. The binaural synthesis process uses the Head-Related Transfer Functions (HRTF) as an input required to assign the directions of arrival to sounds coming from virtual sound sources in the created virtual environments. Generic HRTFs are often used for this purpose to accommodate all potential listeners. The hypothesis of the research is that the use of individual HRTF in binaural synthesis instead of generic HRTF leads to improved accuracy and quality of virtual sound source localization, thus enhancing the user experience. A novel methodology is proposed that involves the use of dynamic virtual sound sources. In the experiments, the test participants were asked to determine the direction of a dynamic virtual sound source in both the horizontal and vertical planes using both generic and individual HRTFs. The gathered data are statistically analyzed, and the accuracy of localization is assessed with respect to the type of HRTF used. The individual HRTFs of the test participants are measured using a novel and efficient method that is accessible to a broad range of users