A wireless microphone, or wireless microphone, is an audio equipment that transmits sound signals. It consists of a transmitter and a receiver, and is usually called a wireless microphone system. Let's briefly introduce the related terminology of wireless microphone system:
This is a microphone placement rule. When using a cardioid microphone and an omnidirectional microphone to receive a sound source, in order to be able to capture the same amount of ambient sound, the distance between the former and the sound source should be twice the distance between the latter and the sound source , And only in this way can we capture a more natural sound.
This is a set of specifications developed by IEEE for wireless local area networks. This set of standards specifies the connection protocol between two or more wireless network systems, including wireless computers and some base station workstations. Several of the more unique 802.11s have been widely used. The most commonly used standards include 802.11, 802.11a, 802.11b, and 802.11g. It needs to be pointed out that 802.11g can be integrated with 802.11b after reducing the data transmission rate (the famous Wi-Fi).
antenna. A conductive device used to transmit or receive radio frequencies (or radio waves), which can be used for wireless transmitters and wireless receivers. It has different shapes, sizes, sizes and configurations, including omnidirectional and several other different polar heads.
Antenna gain is also called antenna directivity. Refers to the signal ratio of a directional antenna to a non-directional antenna. This ratio can be used to measure the effectiveness of a directional antenna relative to a standard non-directional antenna. The measurement unit is dB. The measured value along the antenna is positive and the reverse antenna direction is negative. The ratio has the same reference value when reflecting and receiving signals.
Baxandall Tone Controls Baxandall
Tone controller. The most common components of the positive low-treble control circuit, first appeared in the article "Negative Feedback Tone Control — Independent Pitch Control with Low-Treble without Conversion" by British engineer PJ Baxandall, published in October 1952, 10th issue of Wireless World, page 402 , It should be the originator of the equalizer used in our analog equipment today. Baxandall has a unique design idea. It uses the negative feedback in the circuit to achieve lower harmonic distortion, which is helpful for finer control of the op amplifier. Negative feedback basically works by sending a polarity (the reverse behavior of the output signal back to the amplifier). If the signal is filtered by the component, the relevant frequency range of your male tone controller will be affected.
Bluetooth. A short-range wireless technology that connects to high-frequency wireless transceivers. Like the frequency bands used in industry, technology, and medicine, it uses a frequency above 2.4 GHz. This low-cost technology can not only be applied to headsets, mobile phones and laptops, but also can be used to create a personal local area network. You can connect your computer, printer and audio equipment through Bluetooth, so that you can easily connect to PDAs, etc. Some devices are controlled remotely. The technology was first developed by Ericsson (now acquired by Sony). In 1998, industry giants Intel, IBM, Toshiba and Nokia jointly established a Bluetooth technology professional research organization. Now more than 2000 companies are using or Develop Bluetooth technology. For example, Apple Computer has integrated Bluetooth technology into its keyboard, mouse and other peripheral devices. At first, the larger transmission distance of this technology was only 10 meters, and now this distance has grown to a larger 100 meters. Although the Bluetooth technology protocol is different from Wi-Fi, the frequency bands of both are 2.4 GHz ISM, and the bandwidth is 83 MHz. This technology uses high frequency transmission technology (FHSS), and encounters interference from other signals during transmission. At the same time, it can switch back and forth among 79 different 1MHz-wide channels in the frequency band, thus ensuring the speed and quality of transmission.
A small electronic device that needs to be carried by performers in a wireless system. Its function is mainly to send sound signals to a remote receiver. Of course, in a personal wireless monitoring system, it can also be used to receive remote signals. The structure of this kind of device is usually very simple, mainly composed of some electronic components and a battery specially used to transmit, receive or amplify the signal. Now on the market, some wireless systems have begun to directly build the internal components of this device into a microphone or a small plug that can be directly plugged into a guitar or other musical instrument, thus eliminating the need for performers to carry it with them.
Lotus root. In physics, it refers to a pair of electric charges or magnetic poles with opposite signs or polarities but equal in number, separated by a certain distance from each other. In terms of audio, a lotus-coupling speaker refers to a speaker with two drivers installed in opposite directions and opposite in phase. It is usually used as a side or back satellite device in a home theater surround sound system. The shape propagation mode can effectively improve the enveloping feeling of surround sound. In terms of radio and television, a lotus-coupling antenna is an antenna that connects two half-wavelength rods on an intermediate transmission rod. The most common example is the "rabbit ear" antenna used to receive TV signals. Many wireless monitors or auxiliary monitor systems are now using lotus-coupling antennas.
Diversity receiver. In wireless microphone equipment, the diversity receiver is mainly used to improve the quality of wireless signal reception, and it uses two independent antenna systems. The device can automatically identify the signal from the antenna, and quickly switch to receive a stronger signal after comparison.
Loss of signal. It refers to a phenomenon in which a signal is disturbed. In wireless systems, signal loss refers to an area where the signal level drops below the effective level, causing the receiver to mute (if it is passing through older components, it may emit harsh white noise). In tape recording, dropout refers to the part where there is no signal, which to a certain extent depends on the ability of the tape to withstand the magnetic charge.
Frequency agility. In the communications industry, it is usually used to indicate that the device can be controlled at multiple frequencies, and sometimes it also implies that the device can automatically complete frequency selection. In the industry, this mainly means that the user can arbitrarily change the frequency of the wireless device (sometimes called the channel) as needed. For jobs that require constant movement, this is of great significance, because they often need to constantly adjust and use different frequencies according to the interference that may be received by the TV station and a specific area.
IF. Shorthand for IF. It refers to the mixed signal in which the oscillating signal is mixed into the superheterodyne receiver. In addition, it can also mean that the carrier frequency is converted to a frequency with a medium amplitude during transmission or reception.
Mirror frequency. In a wireless system, an interfering carrier frequency may use a heterodyne tuning system to generate the same intermediate frequency (IF) disguised as a normal carrier frequency, although they are filtered before the frequency enters the system, but sometimes Error reception will still occur, causing the receiver to have to deal with it. The result is some unsatisfactory performance and interference (at least intermittent).
kilohertz. Hertz is the number of frequency cycles per second, and a kilohertz refers to a unit of frequency of one thousand cycles per second. Hertz is the most commonly used parameter in the process of radio frequency and audio signal processing, among which audio measurement usually refers to the audio frequency spectrum (the audible range is 20 Hz to 2000 Hz). Hertz can be used to represent analog waveforms such as electronic, audio, visual, and wireless signals.
led. Abbreviation for light-emitting diode. It is an electronic component that emits light when an electric current passes through it. This component is widely used in various electronic devices, including watches, laser disc players (in fact, the laser for reading discs is also emitted by LEDs), keyboards, meters and readers on DAT machines, etc. In addition, infrared LEDs can also be used on some remote control devices such as wireless headsets.
Sidelobe suppression. In acoustic or wireless transmission technology, Lode specifically refers to the signal emission and microphone pickup pattern that is not spherical or omnidirectional. In fact, Lode is a kind of directional polarity, and its shape is similar to two cones. For example, a microphone with 8 radio modes actually contains two Lobes. They are located on both sides of the microphone. The over-cardioid directional microphone also contains two Lode, the front part of which is better than the rear part. The cardioid pointing microphone generally only contains a Lode with a larger range. Once you focus the emission of energy in a particular direction, this actually forms a Lode. Both wireless transmission systems and speaker systems have this feature. Most of the changes in Lode depend on the wavelength of the sound and the energy of electromagnetic waves.
Phase Locked Loop
Phase locked loop. A phase-locked loop (PLL) refers to the closure of an electronic circuit with an oscillator in which the frequency is constantly adjusted to match the frequency and phase of the input signal (and thus lock).
In terms of audio, it refers specifically to the design and application of filters. The analog filter is designed to integrate some capacitors and inductors based on the interaction with the constantly changing frequency. For example, a capacitor can be installed in a circuit with resistors to make a low-pass or high-pass filter. This is the so-called RC circuit (resistance and capacitor), single-type RC circuit (one capacitor, one resistor) It is a single-pole filter, and so on, a two-pole filter has two RC circuits and so on. A single-pole filter can replicate (plus some phase shifting) a high-pass or low-pass around 6 decibels per octave. For example, in a high-pass filter, the frequency is reduced by one octave, then the signal voltage will be reduced by half according to the formula 20log (V1/V2) by 6 decibels, and the two-pole filter will be reduced by 12 decibels accordingly. In a band-pass filter, the more poles, the higher the Q value. For resonance filters that often appear in synthesizers, more poles means higher resonance. Nowadays, digital circuits and software can simulate the function of the pole through a specific algorithm, and the software can also reduce the amplitude of the frequency through a method completely different from the traditional filter, so that the user can realize some aspects of the complex signal. More control, resulting in many unique audio characteristics.
Repeater. A device that can amplify or update the data stream transmitted on the network so that it can be transmitted to more remote receivers. In general, the longer the signal transmission distance, the worse the quality, and eventually it becomes unusable. According to the different intentions of users, there are many types of repeaters. For example, some wireless communication systems such as mobile phone signals use repeater sites to expand transmission coverage. In an optical fiber system, a repeater is generally composed of a photocell, an amplifier, and an LED that forwards data. In a digital system, the signal is often recognized and then transmitted. This is mainly to avoid the phenomenon that some noise and distortion are also amplified when the signal is amplified. When the digital signal is recognized and re-transmitted, its effect is the same as the newly sent signal. Many synchronization devices have the function of Jam synchronization, so they can all be used as a repeater.
Noise suppression, squelch. In radio receiving systems such as wireless microphones and guitars, users can set thresholds for carriers below a certain level, or directly set a mute function. It can eliminate some noises generated by radio receiver debugging and signal forwarding. Typically, the squelch control may cause the receiver to mute, which places higher requirements on the energy of the carrier during operation. If the squelch threshold is set too high, the audio will be muted from time to time, but if it is set too low, then bursts of noise may appear when the sound loses part of its quality for some reason. Nowadays, people rarely need to perform noise suppression manually, because modern technology has provided us with many simple and effective methods.
Stage monitor. A loudspeaker set in the stage performance area to assist performers in performing. Stage monitors come in many shapes, styles and forms. The most common one is wedge monitors, which are generally set on the floor of the stage and face the performer from various angles. Different bands have different requirements. Some require each member to have an independent monitor, while others require a row of monitors in front of the stage. In addition, a monitor is called a Side fill monitor, which is usually installed on a stand. As the name suggests, this monitor is to fill the entire stage with sound. There is also a kind of monitor called an in-ear monitor, which is a headphone-like monitor that can cover the entire ear. Many drummers choose this kind of closed headphone monitor because they need to perform according to various rhythm tracks. Playing.
Threaded connector. The abbreviation for threaded connector is a connector commonly used for coaxial cables. Basically, it is a linear version of BNC, but its linear characteristics make people feel that it has better connection capabilities than BNC-coupled connectors. The higher the frequency through the connector, the more critical the quality of the connector. Many wireless systems have adopted TNC connectors as the input interface of the antenna.
Transmission loss. It refers to the loss of the signal in the process of transmitting from one point to another store. For example, loss will occur when the signal passes through walls and ceilings, and loss will occur if the transmission distance is long. Even the resistance, inductance and capacitance of the conductor itself will cause transmission loss, so when the transmission distance is long We often need some special equipment (such as: repeater) to reduce loss and maintain the quality of the transmitted signal.
Automatic selection. A term for wireless microphones. It is a high-quality form of diversity receiver. An automatic selection radio receiver is designed with two independent receiver components. Each has an independent antenna for receiving the signal from the wireless microphone, and the two antennas can also automatically Compared with choosing to receive a stronger signal, it effectively enhances the stability of the signal received by the receiver, because it is almost impossible for the two antennas to experience signal loss at the same time under normal circumstances.
Ultra High Frequency
UHF. Like VHF, UHF is also a frequency band or radio frequency range defined by the FCC (Federal Communications Commission). It is usually used in some TV stations and various wireless two-way communication systems. The frequency range of UHF follows the upper limit of VHF, from 300 MHz to 3000 MHz.
Very High Frequency
VHF. VHF is the abbreviation of VHF, it is a frequency defined by the FCC (Federal Communications Commission)
Segment or radio frequency range, it is usually used in some TV stations and various wireless two-way communication systems. The frequency range of VHF is 30 MHz to 300 MHz.
Wireless system. Refers to a system that realizes wireless data transmission between points. The most typical example is a radio frequency system. The signal is modulated by the transmitter and then transmitted to the receiver. After demodulation, it is converted to a common frequency. But in some cases, "wireless" seems to be a little misused. For example, in a wireless guitar system, there is not really no one wire. In fact, it has two wires, one connecting the guitar and the transmitter, and the other One connects the receiver and amplifier. In any case, wireless technology has been widely used in various fields today, and with the continuous advancement of technology, there will be more creative applications.