| Popis: |
The common method in audio player for sound generation with a loudspeaker is driving analogue electrical signals while this thesis will study an alternative method for application of a loudspeaker with digital signals. This thesis found feasibility of driving loudspeaker with digital pulses according to the concept of Multiple‐level Digital Loudspeaker Array (MDLA) and discovered generation of sound from ultrasound with potential.The concept of a MDLA can be applied as an alternative method to produce Amplitude Modulation (AM) sound. The new concept extends from Digital Loudspeaker Array (DLA) by application of Pulse Width Modulation (PWM). By Application‐Specific Integrated Circuit system (ASICs), the clock speed would reach 1 GHz. With the chip, DLA will require only 7 speaklets for the reproduction of 16 bit audio.A novel concept of sound generation from ultrasound originates from the concept of AM sound of Audio Spotlight technology. The new concept applies mechanical amplitude emodulation for improvement in efficiency of sound generation.A rectifying loudspeaker is introduced for sound generation according to the concept. The loudspeaker uses a secondary source as the main source of sound generation, while vibration of the primary source is applied for speed control of air particles like a valve. The structure of the loudspeaker is adapted from the human voice system and can be fabricated by MEMs. |
