Introduction to multimedia speakers

Multimedia speakers, commonly known as "computer speakers". Compared with traditional speakers, it has the characteristics of small volume and easy operation. It can meet the multimedia application needs of ordinary consumers.

Speaker introduction

principle

The sound file in the computer converts the digital audio signal into analog audio signal through the sound card, and then outputs it from its output port. At this time, the audio signal level is weak, generally only a few hundred millivolts, which can not push the speaker to work normally. The voltage to push the horn to work normally generally needs a voltage of about several volts. At this time, it is necessary to amplify the small signal output by the sound card through the amplifier (commonly known as the power amplifier). The amplified audio signal can push the horn to convert the audio electrical signal into sound wave.

Now the newly launched USB multimedia speaker does not need a sound card. It introduces a digital audio signal through the USB interface output of the computer, and then the USB multimedia speaker converts this signal into a pseudo audio signal through the internal special usbic chip, so as to realize the function of replacing the sound card.

form

1. Interface part

It needs an interface part connected with the sound card in the computer chassis (if it is a USB speaker, it is connected with the USB interface of the computer). In this way, the sound signal output by the sound card can be introduced into the speaker amplifier. Usually, the interface part is composed of a two-core shielded cable with three core plugs at both ends (if it is a USB speaker, it needs a special cable for USB interface).

2. Amplifier

The second part is the amplifier. Its function is to amplify the weak audio signal sent by the sound card (or output by USB chip) to promote the normal sound of the horn. At the same time, the amplifier also has control functions, such as volume control, treble and bass gain and attenuation control, and some amplifiers add sound field control, such as SRS.

3. Speaker

One part is the speaker, which is responsible for changing the audio signal sent by the amplifier into sound waves, The speaker is composed of a box (usually made of wood and plastic) and a speaker unit. If the amplifier and the speaker are independent, we call this kind of speaker a passive speaker: if the speaker and the amplifier are assembled together (usually the amplifier is installed inside the speaker), we call this kind of speaker active. Most multimedia speakers in the market are active speakers, because the manufacturing cost of active speakers is relatively lower than that of passive speakers. However, the sound quality of passive speakers is often poor (including independent amplifier) shall be higher than the active speaker. If it is a USB speaker, a USB audio decoder and control part shall be added to the multimedia speaker.