RH-AUDIO

  Compared with Class A/B amplifier,  class d Pa amplifier   has poor audio performance. It not only has large distortion, but also has narrow dynamic range. Therefore, the current designer of class d Pa amplifier must improve its performance. By integrating high-performance sampling rate converter (SRC) and_-processing technology, the new generation of solutions can greatly improve the distortion (THD+N), and the dynamic range is over 100 dB.   Nowadays, one of the noise sources of class d Pa amplifier is the jitter of the audio sampling clock. Clocks are usually generated by SOC (MPEG decoder, DSP, etc.). Even small jitter can rapidly affect the performance of conventional class D amplifiers, because the audio clock is associated with the output clock of the modulator.   One way to solve this problem is to use SRC technology. Because SRC uses locally stable clock sources to synchronize digital audio clocks, such as quartz crystal oscillators, So the output jit...

  Class D Pa amplifier  drives the amplifier of loudspeaker by controlling ON/OFF of switch unit. Class D Pa amplifier was first proposed in 1958, and it has become popular in recent years. Class D Pa amplifier has been greatly developed in the past few generations. System designers have greatly improved the durability and audio quality of the system. Digital amplifiers improve audio quality and system performance. In fact, for most applications, the benefits of using these amplifiers far outweigh their disadvantages.   In traditional Class D Pa amplifier, analog or digital audio signals are converted into PWM signals by a controller before being amplified by power MOSFET tubes integrated into power back-end devices. These amplifiers are highly efficient, use very small radiators or do not need radiators at all, and reduce the power output requirements. However, compared with traditional class A/B amplifiers, they also have inherent cost, performance and EMI problems. To ...

  Compared with class AB amplifier,  type D amplifier  has higher efficiency and better thermal performance. Nevertheless, the heat dissipation of type D amplifier still needs careful consideration. This application note analyses the thermal performance of type D amplifier, and illustrates the principles of good design through several common examples. When evaluating the performance of type D amplifier in laboratory, continuous sine wave is often used as signal source. Although it is convenient to use sinusoidal wave for measurement, such measurement results are the thermal load of the amplifier in the worst case. If the type D amplifier is driven by a continuous sinusoidal wave near the maximum output power, the amplifier will often enter a thermal shutdown state.   Amplifier Performance - Compared with G-type boost power supply commonly used in smart amplifiers, the integrated H-type 11-volt DC-DC boost converter can improve the power supply voltage and maintain hi...

  We already know that the acoustic signal is to convert the waveform of music into the waveform of electrical signals, so we can also make the sound of music by pushing the waveform of the signal into the air as well. The equipment in the audio system that converts electrical signals into sound is the "amplified speaker", which is commonly known as the "speaker". At present, the most mainstream technology for converting electrical energy into sound waves is electromagnetic. The amplified speakers on the market today are mainly designed and produced to take the electromagnetic principle.   The complete   amplified speakers  will  consist of several parts: the speaker unit, the crossover network, and the speaker. The speaker unit basically reverses the working principle of the microphone. The electrical signal is input to the coil on the voice coil in the magnetic system. The coil will change magnetically with the signal, and drive the voice coil to move in the m...

  1. Background A amplified speaker is a device that converts electrical energy waves into mechanical energy waves or audible sound. Sound is produced by the vibration of an object. This vibration creates a series of ripples or waves, like throwing a stone into a pond. A amplified speaker reproduces sound waves (or audio) at various frequencies. The frequency is the rate at which particles in the air vibrate. The human ear can hear sound from about 20 hertz (Hz) to 20,000 Hz or 20 hertz (kHz).   Amplified speakers   can be used in all types of communication and entertainment equipment, such as radio and television receivers, tape recorders, telephone answering machines. Baby monitor and stereo home entertainment system.   2. History Since 1874, Ernst Siemens applied for a dynamic amplified speakers, its fundamentals have hardly changed. Siemens described his invention as a device for obtaining mechanical movement of an electric coil from the current flowing through i...

  3 、 Materials The dynamic speaker has not changed in decades. The frame is made of stamped iron or aluminum. The permanent magnet is a ceramic ferrite material composed of iron oxide, strontium and a ceramic binder. Cones, surrounds and star wheels are made of adhesive-treated paper. The voice coil consists of a plastic winding tube and a coil wound with thin and insulated copper wire.   4. Design The most common amplified speaker is the dynamic speaker. It consists of a frame, a permanent magnet, a soft iron core, a voice coil and a cone. The frame supports the cone and permanent magnet assembly. The voice coil consists of an insulated wire wound on a plastic spool. One end of the spool is attached to the cone and the body of the spool slides over the soft iron core.   The wire from the voice coil is connected to the audio amplifier. When the audio signal from the amplifier is applied to the voice coil, an electromagnetic field is generated around the voice coil. This ...

  5 、 Manufacturing process (1) Permanent magnets are made by mixing iron oxide with strontium, then grinding the compound into a very fine powder. The powder is mixed with a ceramic binder and then sealed in a metal mold. The mold is then placed in a furnace and sintered to bind the mixture together.   (2) The frame is made of aluminum or steel. The sheet arrives at the intended factory, where it is then placed on a conveyor belt and conveyed to a cutting machine. The cutter uses a hydraulic press to cut holes in the sheet to allow air to move freely from the cone. The sheet is then formed by a hydraulic press, which forces the sheet into a mold of the desired shape and then drills the mounting holes in the appropriate locations.   (3) Cones: The surround and the star wheel are each made of laminated paper and are then glued together as components.   (4) Voice coil: The voice coil is made by winding many very thin insulated copper wires on a plastic spool. The spool...