Digital audio equipment :What is DSP digital signal processing technology ?

The audio industry is in the transitional stage from the analog audio stage to the digital audio stage. Digital audio has become an inevitable development trend of audio. Digital products are now being widely used in society. With the new generation of products, audio technology has shifted from traditional analog technology to digital audio technology.

The digital devices we often use now are: digital mixers, digital processors, digital karaoke effects, etc.,

In any smart digital system, the processor responsible for computing all kinds of data is the core of the center, and it is no exception in the audio system. In recent years, whether professional stage audio, home audio or car audio, digital audio processor DSP (Digital Signal Processer) has made great development, technology is changing with each passing day, and its application is becoming more and more widespread and popular.

The full name of DSP is Digital Signal Processor, that is, digital signal processing technology. Digital signal processing is the use of computers or special processing equipment to collect, transform, filter, estimate, enhance, compress, and identify signals in digital form to obtain a signal form that meets people's needs. DSP chip refers to the chip that can realize digital signal processing technology.

The working principle of DSP is to receive analog signals and convert them into digital signals of 0 or 1. Then modify, delete, and strengthen the digital signal, and interpret the digital data back to analog data or actual environment format in other system chips.

Compared with analog signal processing systems, digital signal processing systems based on general-purpose DSP chips have the following advantages:

(1) High precision, strong anti-interference ability and good stability. The accuracy is only affected by the quantization error, that is, the limited word length, the signal-to-noise ratio is high, and the device performance is small. It is less affected by external factors such as temperature and environment.

(2) The programming is convenient, and it is easy to implement complex algorithms (including adaptive algorithms). The DSP chip provides a high-speed computing platform that can realize complex signal processing.

(3) Programmable control, when the function and performance of the system change, there is no need to redesign, assemble, and debug. Such as the realization of different digital filters (low pass, high pass, band pass); radio communication in different working modes in software radio; filters and spectrum analyzers in virtual instruments.

(4) The interface is simple, the electrical characteristics of the system are simple, and the data flow adopts a standard protocol.

(5) Convenient integration.

(6) It can realize functions that cannot be realized by analog processing: linear phase, multi-sampling rate processing, cascading, easy storage, etc.;

(7) Can be used for very low frequency signals.

The emergence of digital signal processors has given rise to the emergence and rapid development of digital signal processing technology. In terms of audio quality, after digital audio is converted through analog-to-digital/digital-to-analog conversion, the closer to analog the sound quality is, the better. Great advantage.

Since digital signals are not subject to loss and interference like analog signals during transmission, more and more audio products use digital input interfaces, such as CD players and DVDs.

In the function of audio equipment, DSP is mainly responsible for adjusting and correcting the input signal and output signal of different channels, including frequency division setting of frequency band, slope setting of crossover point, mixing, division, delay playback and different EQ equalization of frequency points, etc., allow users to solve the bad sound effects in audio playback through these adjustments, and shape the sound form they need, and get the pleasant listening feeling they need.

Friends who know a little about professional audio will immediately think of it: aren’t these DSP functions similar to a “mixer”? In fact, DSP, to a large extent, does play a role similar to a mixer. Compared with traditional mixers that electronically correct the signal current by circuit means, DSP uses digital chips + computer software to digitalize the signal. Adjustment, small footprint, convenient operation, and the adjustment accuracy is often higher, and the functions are more comprehensive and rich, so the scope of application is naturally wider. For example, in recent years, in the fields of professional stage audio and venue audio, DSP equipment has gradually replaced In order to gain the market share of traditional mixing consoles, some newly introduced mixing consoles have often been deeply integrated with DSP software, which more reflects the attributes of DSP consoles.