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 on page 402 of the tenth issue of Wireless World in October 1952. It should be the originator of the equalizer used in our analog devices today. Baxandall has a unique design idea. It uses the negative feedback in the circuit to achieve lower harmonic distortion, which helps to control the op amplifier more accurately. Negative feedback basically works by sending a polarity (the reverse behavior of the output signal returning 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 high-frequency wireless transceivers. It uses frequencies above 2.4 GHz, just like the frequency bands used in industry, technology, and medicine. 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 computers, printers and audio devices via Bluetooth, so that you can easily connect to PDAs, etc. Some devices are controlled remotely. This 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. Today, 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 maximum transmission distance of this technology was only 10 meters. Now this distance has grown to a maximum of 100 meters. Although the Bluetooth technology protocol is different from Wi-Fi, the frequency band of both is 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 the transmission process. At the same time, it can switch back and forth among 79 different 1MHz-wide channels in the frequency band, thus ensuring the transmission speed and quality.
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 specially used to transmit, receive or amplify the signal and a battery. 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 recognize 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 a wireless system, 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 users can arbitrarily change the frequency (sometimes called channel) of the wireless device according to their needs. 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 intermittently).
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 radio frequency and audio signal processing. Audio measurement usually refers to the audio frequency spectrum (the hearing 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 equipment, 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).