What type of teaching amplifier is used in the classroom now, and which one is better?
The first handheld microphone: cable and cable seat wheat (or gooseneck microphone)Advantage: the teacher does not need to bring any equipment, the school management is simple, the purchase and use of the lowest cost;Disadvantages: mouth to close talking microphone requirements (1~5 cm); teachers will be fixed on the desk, not easy to do body language, it is difficult to achieve vivid teaching; the use of wired handheld microphone, a teacher occupied a hand, also because of pulling a string, the teacher activity range is limited, so it is more difficult to do body language;
Fourth: there are electromagnetic radiation, so that teachers and students in a long period of strong electromagnetic radiation teaching environment, the health is not fully guaranteed;The use situation of Classroom: because of the wireless amplifier was the earliest, so there are still many schools to install such equipment, but many are not in use or maintenance, the utilization rate is not high (portable FM wireless amplifier for temporary use of a few), equipment is gradually being replaced by other new wireless systems, not installed in the classrooms, often no longer consider using this device;Fourth: Pocket megaphoneAdvantage: the fixed power amplifier and loudspeaker design into small mini type plastic box, let the teacher like the same pocket tied at the waist to solve a wide range of cable amplifiers cannot move, can not fully display the body language, at the same time to buy low cost, use cost is low (rechargeable)Weakness: First: because the teacher hangs a loudspeaker box, the volume and weight can not be too large, but also to speakers with dry batteries or batteries, so power can not be big, so the sound is not big;Second: because speakers and microphones are very close to, it is easy to whistle, so you can only use the head microphone to wear, many glasses teachers and female teachers do not accept;Third: the speaker face turns with the person's turn, the student hears the sound can be big, small, the sound effect is bad;Fourth: because most purchase object is individual teachers, so as to consider the cost, most pockets megaphone of poor quality, easy bad, sound effect;Use of Classroom: in the economic conditions are relatively poor in school, because the school did not match other types of amplifiers, part of the teachers and teaching needs, amplifying the so many teachers, is to choose the most expensive for the temporary use of amplifiers;
Third: FM wireless amplifier (V wireless and U wireless)Advantage: for wired amplification (interface microphone, frequency shift repeater cable, a handheld microphone cable Michael) can not be used in the classroom in a large range, FM wireless microphone system is the use of FM radio similar technology to develop wireless PA system, can use the wireless microphone into the classroom anywhere while walking speaking, fully display the body language, according to the frequency range and V wireless U and wireless;Disadvantages: First: in the same school, the number can not use too many (such as more than 30), too much is prone to string frequency phenomenon, the trend of modern education is the focus of the school, the classroom teaching building more and more, the more easy to cause the phenomenon of string frequency;Second: vulnerable to environmental electromagnetic waves, signal interference and other factors, such as weather effects, often breaking sound, noise and other unstable phenomenon of expansion;Third: wireless microphone frequency point is not universal, and sometimes need FM point, brought the management, maintenance, unsanitary and many other troubles;
The second type: frequency shift amplifier on the interface microphoneAdvantages: the teacher does not need to bring any equipment, the school management is simple, the teacher can move on the platform in a small range, without the mouth to the interface microphone speak very closely, it is an extension of wired microphone;Disadvantages: in order to improve the sound of the microphone pickup distance (5 meters), we must increase the sensitivity of the microphone, the inevitable result is that: first, at the same time PA, will also be environmentally sound intake, to separate ambient sounds and human speech sounds, at present no one can do equipment frequency shift repeater, sounds very noisy, although the increase in the number of interface microphone many products, let the people close to the microphone, the microphone does not work so far away from the people, but it is difficult to completely eliminate background noise;Second: interface microphone sensitivity is very high, the classroom and speakers, the most easy to form the acoustic feedback, squeaking, in order to overcome this problem, the sound frequency shift repeater is the speech shift 3~8MHz to suppress howling, but the resulting speaker sound serious distortion, greatly damage the sound, when talking with serious "buzzing" end; third, although the teacher can use the platform in small range, the teacher walked off the platform, then amplifying failure, therefore the range is not big.The use situation of Classroom: PA due to serious distortion, at the same time with a serious "buzzing" sounds and noises, for most of the pursuit of personalized and pay attention to the effect of the young teacher lectures more and more do not accept this kind of inferior quality, the equipment will be phased out in the modern classroom, Chinese in countries outside rarely use this equipment;
