No sound may be a computer: the computer does not sound: basically does not occur, the current board is integrated sound card. Or inherently bad. Ha ha. Computer has no sound may TWO: Headphones question: Replace one last try on another machine. Computer has no sound might III: the sound is turned off: look at the bottom right of the voice icon, smart classroom speaker equipment, is not sound is turned off or the minimum volume to be pulled up. Open on the line in other words, the speaker used in intelligent office systems, subwoofer belong to sound, but not all sound. 7.1 In general, speakers, 2.1,5.1, that point 1 is subwoofer. Center Front Surround HAIR treble, bass subwoofer hair, from the unit will be able to see the difference between the structure, lz if you want more sound knowledge of aspects of sound can go and see the forum talking about monitors, speakers applied smart home, many people are heard inside the field of professional audio, which is still unknown. This is from the speaker to talk about classification, generally divided into the main speakers use according to the playback speakers, monitors and back to listen to several speakers. Speaker, Wuhan sound engineering, intelligent conference room speakers by Wuhan Engineering Co., Ltd. Jiuhua video. Speaker, Wuhan sound engineering, intelligent conference room speaker Video Jiuhua Wuhan Engineering Co., Ltd. (www.jowa-tech.com) this year introduced a new upgrade, the above picture is for reference only, please call the contact or pictures on this page phone, for the latest information, contact: Mr. Lu.