Class D amplifiers have always offered better efficiency than Class AB amplifiers for low-power applications. This inherent advantage, however, rarely outweighed the traditional disadvantages of Class D, which were higher cost, reduced audio performance, and the need for output filtering. Recent advances in Class D technology, however, have brought Class D costs and audio performance up to equa...

Douglas Self’s writing on audio power amplifiers provides the reader with invaluable information. Not only does he teach the fundamentals (and details) of power amplifier design per se but also discloses a systematic approach to analyse the distortion performance of typical amplifier topologies. The latter is particularly important as systematics does not appear to be a natural thing in audio c...

purpose: this study aimed to identify and introduce the most important evaluation and production criteria of audio books based on users’ point of view.method: in terms of methodology, this study was among the quantitative studies and done with descriptive survey. the research instrument was researcher-made questionnaire. population was all users of audiolib website that used from audio books mo...

We have found that sounds containing high-frequency components above the human audible range (20kHz) significantly increase the regional blood flow in the deep-lying brain structure and the power of the alpha frequency range of the spontaneous electroencephalogram (EEG), and positively affect sound perception. We have termed this phenomenon the “hypersonic effect” [1]. To carry out further expe...

this study sought to investigate the impact of teaching speech acts and role relations through authentic audio-taped and video-taped materials on the level of iranian efl learners’ pragmatic competence. to this end, 55 intermediate learners were ed and randomly assigned to two experimental groups: the audio-taped group and the video-taped group. during the treatment, the audio-taped group recei...

The fundamental problem of pulse-width modulation (PWM) based open-loop digital Class-D audio power amplifiers is the inherent nonlinearity of the PWM process, which necessitates the application of a precompensating linearization algorithm. Severe technical difficulties arising from the stringent speed requirements of both electronic circuitry, and digital signal processing devices make the imp...

in this paper, we investigate the parameters affecting total harmonic distortion (thd) and power supply rejection ratio (psrr) in pwm class d amplifiers (cdas) on the basis of linear models with feedback. from our mathematical analysis, we show that the thd of a pwm class d amplifier with feedback can be improved by increasing the gain of the integrator through adding another amplifier at the o...

The power requirements imposed on the amplifier by piezoelectric actuators is discussed. We consider a two-degree-of-freedom mechanical system driven by a piezoelectric stack for the purpose of analyzing power flow and power dissipation of four amplifiers. Two of the amplifiers are benchtop linear amplifiers. The other two amplifiers are based on switching topologies. The power consumption of a...

In der digitalen Audiotechnik werden für bestimmte Zwecke linearphasige Filter benötigt, die man sehr einfach mit Hilfe von FIR-Filterstrukturen realisieren kann. Bei hohen Anforderungen können dabei sehr hohe Filterordnungen auftreten, die zu einem hohen Aufwand sowie erhöhter Verlustleistung führen können. Mit Hilfe der Modellordnungsreduktionsmethoden ist es möglich, den Aufwand bei der Impl...